When I restored the pneumatic stack in my Cremona G, I initially set
the valve travel around .035".  After bench testing it for power and
repetition, I found several pneumatics were weak and needed more travel.

I cannot remember exactly what I ended up with but I do remember
these valves needed more travel than other pianos I had rebuilt.  And
yes, mine seemed to have quite a lot of travel before it was rebuilt,
perhaps indicating it originally had a good bit of valve travel.

If I had to guess I'd guess I settled for about .042", but it's best to
test your stack on the bench and find what works best for your stack.

Randy Hayno