I agree with the above posts, looks like you've gone about as far as you can with stem and seat post changes. I hated to swap out the beautiful Ambrosio stem from my '64 Legnano for a Nitto, but it worked out pretty well. Higher and a little longer in reach.

Back in the day there was less me and more bike. I've had the bike 53 years. Time for you to probably swap frames. With me it was sentimental value, and the fit wasn't that far off. I got lucky a few months ago and came across a '73 Raleigh Super Course that fits like a custom made frame (bottom picture). They are out there, you might get lucky. I'm right at 6 ft, the Legnano is 56cm, and the Raleigh is 23 1/2 inches. I've never given crank arm length much thought, but these are both 170s, though the top Campy crank arm looks longer because it's thinner than the Sugino below.