i am trying to find a second portafilter and double shot basket for my 1980's vintage Pavoni. it must be the correct size and have the included spring shown in the photo. i have been told that the newer portafilters after 1990 do not fit.

Normally I would point you to Stefano's espressocare.com site:
http://espressocare.com/Qstore/Qstore.c ... 1202481787
That is the pre-millenium portafilter. It's currently out of stock, but you could probably email Stefano to find when it might be available. The new portafilters aren't cut for the basket retainer spring anymore though.

Once in a while you do see these show up on eBay, so if you keep a search checking for La Pavoni portafilters it will probably show up again. A recent portafilter with the retainer ring went for nearly $120 on ebay.
http://www.ebay.com/itm/201018606767

Actually the 1974 to 2000 groups were produced with at least two different portafilters. One style has a 10mm thread to hold on the handle, the other 12mm. The early style is the 10mm one, and the alloy appears to be quite different than the later ones. I have a 1978 machine and 1999 one. The two portafilter types interchange nicely on mine at least.

I would not want a spring inside these portafilters because I NEVER tamp espresso with the basket in the portafilter. I would remove it and discard it if either of mine had one! The best way to avoid spongy pulls is to keep the portafilter on the machine while it is warming up without the basket. After the group is bled and up to temperature, I remove the portafilter, put the basket containing the packed espresso into the portafilter, raise the handle until steam JUST begins to be released, lower it just enough to stop the steam release, quickly put the portafilter on the machine, and then raise the handle all the way to allow the group to fill. Then pull the shot. This technique minimises, in fact, eliminates spongy pulls. It also speeds getting that first cup! (Which in my case is often the only cup!!)

rpavlis wrote:I would not want a spring inside these portafilters because I NEVER tamp espresso with the basket in the portafilter. I would remove it and discard it if either of mine had one!

I've always kept my baskets out of the PF while tamping too, but with my Ponte Vecchio, I use a bottomless PF, and for that, I really like having a retaining clip. It's easy to slip the tamped basket in, and knocking out a spent puck is a bit easier while the basket is being held in place by the clip. Once dumped, I just push on the bottom of the basket to pop it out of the PF. Rinse the basket, and it's ready for another round.

If you're going to "chop" this new PF once you've found one, I'd recommend getting one (if you have a choice) with a retaining clip. As rpavlis said, you can always get rid of it later.

There are a lot of people looking for a 2nd La Pavoni pre millennium portafilter so plan on spending real money for one, they do not go cheap.

Thank you for the information. I know they are hard to find.

Thank you for all the info. I need to refine my technique anyway and will try it your way and see what happens. However I really like the clip. It prevents the basket from tumbling out when I dump the grounds.

Probably not going to chop the portafilter. I am happy with my shots after I took the spout off the bottom.

Wonder if the naked portafilter craze is the reason for the shortage. Guess a lot of these are going through the hole saw meatgrinder.

If you find one of these without a clip and you really want one, someone with metalworking tools can score a groove that will hold a clip. I think you need a lathe for that or a milling machine. Not sure whether either or both would work.