Very nice frame and glad too hear it fits you well. I think these frames were designed with comfort in mind but still stiff enough for light racing, either way a great frame. BTW a friend of mine has just bought a NOS Palosanto here in London but in a small size, 49cm seat tube X 52cm top tube with a carbon fork, unfortunately not a steel fork. Shame you find the frame not so good with climbing, like you mention it could be down to the seat tube angle... I checked my Marcelo seat tube angle and that's supposed to be 73.5 degrees, TBH I don't notice any problems climbing but the rear triangle is very stiff so that may make some difference?.
I'm not disappointed at all,this was the geometry perfect for riders like Indurain,they were usually to ride on the saddle also climbing the Alpe d'Huez and in vey long stages.
I recognize this ad adeguate myself in climbing on the saddle and not frequently on the pedals.
comparing your Pegoretti to this palosanto is very hard,too many differences,in tubes,geometry and fork.
btw I like a lot the bikes nearly as possible to the champion bikes,so I'm very satisfied.