Of course, your version 1.1 Cremina had the older base that was essentially flat, with now real drip tray indentation. I like your point about La Pavoni mixing and matching parts of machines that were assembled with manufacturing dates close to each other.

Do I think there was a quality difference between the earliest machines and the later ones? It seems that my 1961 Europiccola has gorgeous fit and finish and chrome plating that seems very thick. But then it was barely used. Did the later ones have less chrome? I dunno.

Yes, I think mine's identical to a Caferina except the badge. And we can only guess that this was a company that was acquired by La Pavoni.

If it comes down to quality, I'm happy with any 1st gen with an aluminum base. They don't yield with the lever pull.

I think the stamped metal base machines have an advantage with stronger heating elements and especially when they introduced pressure switches because they don't as easily overheat. I've tried my 1972 machine with a pressurestat and the base can get pretty warm.

The distance from the bottom of the portafilter to the bottom of the recess in the drip tray is 1cm bigger on my v1.5 compared to my v1.6. That's the biggest difference between my two models. No real new information here. I agree with the comments in this thread. Different parts likely came from different manufacturers. These parts have slight differences (which isn't surprising). I consider both of my 1st Generations to be little gems. Quirky little gems but fun, solid keepers. I don't need two of course. And 'm actually finding that they can work almost the same. Using the Maximo setting on the one with the 220 volt element seems to work almost like using the one equipped with the new Stefano's steel element, set on Minimo. Essentially I've also concluded that the 220 volt one heats up way too slow on Minimo to really be useful for much. Also, that the new steel element one, if set on Maximo, is not a setting that I would keep on for very long. Water spurts out the OPV. I've tried both the steel ball and the white tip, neither reduces this problem. Any suggestions on how to fix this other than put less water in the boiler? Or, just get used to turning to Minimo as soon as necessary? I haven't found any other suggestions. Thanks.

^ ^ ^

This.

Also, I don't replace the steel ball and spring but clean the steel ball and shim the spring to get it to desired brew pressure, which I test using a steam wand pressure gauge in my machines that don't easily accept one, such as the 1964 machine with no sightglass screw.

Thanks for the input and advice, baldheadracing and drgary.

I've been doing some experimentation on my v1.5, the one with the new steel element from Stefano's.

For each experiment I had the same amount of water in the boiler, about 1.5cm below the top of the sight glass (that you can see), that is, just below the welding seam on the boiler.

I used 2 different springs. Both have about the same number of coils, about a dozen or so. One spring is a bit longer, the newer one. The original spring is slightly shorter. And then I tried different combinations with the White Plastic Tip and the original metal ball.

Here's the results:

1. White Plastic Tip/Short original Spring: On Maximo, water spurt out of OPV.

2. White Plastic Tip/Long new Spring: On Maximo, thermostat kicked in shutting off machine.

3. Metal ball/Short original Spring: On Maximo, some spitting out of OPV but no water spurt. On Minimo a gentle hiss/whistle.

4. Metal ball/Long new Spring: Same as 3 above but noisier, kind of a humming or vibration sound. On Minimo, same as 3 above but with perhaps a slightly stronger hiss/whistle.

I'll try 4 for a while until I get more familiar with its function, then perhaps try 3 again to see which one is ultimately the better one for my morning cappuccino.

Thanks again.

What pressure are you measuring? If the spring resistance is too stiff or too soft you're out of range. Aim for about 0.8 bar pressure. Also the nut may need a whack with a wooden spoon or something similarly soft to loosen it up, assuming you've taken care of any scale.

I took this part of the machine (and most other parts) apart and cleaned them all up as best I could with a brush and then with some citric acid. I didn't remove the last part of the OPV system that was attached to the boiler as I had read that this was a bit difficult and likely unnecessary if it was already firmly attached, which it was. So, I think all is clean here. Would you whack the nut with a wooden spoon even if you had taken it apart and cleaned it all? Is this something that I should still do?

I'm married to an Ethiopian and learned coffee through her family and culture. I'm also a bit of a minimalist and a Luddite. I appreciate the 1st Generation Europiccola's because they're simple and hard to make a bad espresso on. Most and many approaches will result in something quite acceptable. I was brought up to waste nothing. So, "sinking" a cup isn't much of an option for me no matter how bad it is. You might be surprised at what I've managed to drink so far in my espresso journey! (Nor is wasting perfectly good beans in order to season a grinder for example.)

I'm not measuring any pressure as I have no gauges on the machine. Perhaps I'm missing out but I'm content to just experiment.

I also wash my beans before I roast them. And I extract almost everything out of the grounds short of the cellulose!

Reading this website, I can see that there's lots of things that I do that are "incorrect". And that my tastes are unrefined. My mileage does indeed vary.

But I do appreciate all of the advice, information and assistance that is available. Thanks drgary, and many others, for that.