I have noticed the pump pressure on the built in gauge of my Elektra Sixties T1 goes to max when I am pulling a shot. Even when I let it run with an empty portafilter, the gauge still jumps to the maximum. I have read ideal pressure is around 9 Bar.
Do I need to adjust this on the machine and what is the adjustment mechanism on this machine?
Is the reading on the gauge to be considered accurate, or do you really need a manometer to carry out an accurate test?

Thanks for anyone who can help an espresso newbie out here.

The sanity check to the what the gauge says is how it tastes. On my machine, anything north of 10 would be so bitter it would take days to get the taste out of your mouth.

That said, I would take a high gauge reading as valid, even though it might taste ok. I am not familiar with your machine, but I would get it serviced, or replace the gauge and see what the new one reads. We don't want to see what we call a chocolate bomb espresso shot being an actual bomb in the kitchen.

If the shot was bitter, I would turn it off immediately and get it serviced. If it's making a great shot I would take my time look for options and get it serviced sooner than later.

I have adjusted the screw on the rotary pump, which was turned all the way in, turning counterclockwise a few whole turns until the pressure flattened out at 9-10 bar during the extraction and the shot quality has improved immensely.

Great news!

While you're at it, I suggest you decrease pump pressure until you're in the 7.5-8 range. You may find that shots become sour. Sour is the "don't go any lower on pump pressure than this" setting.

Knowing this range, between where you are and the lowest pressure will allow you to make those little tweaks that bring out amazingly different nuances in the roast you're using.