Antique Soprano Sax : Impressed, with one caveat

I've been playing Alto (Yamaha YAS62) for a few years and bought this economy instrument as a more economic alternative to renting . Even if I did not get on with it after a few months I could resell with a small loss.

For the price this is a very good instrument, I understand it is likely based on Yangisawa soprano. I do not use the supplied mouthpiece (I replaced with Yamaha 6C and a Vandoren no 2 reed).

I found it plays in tune even in high register. The keywork is nice and easy, after slight adjustment of the low C and Eb roller keys. Moving from the Yamaha alto was not too difficult, the main issue I have is adopting a different posture while playing, which is of course not a fault with the instruments ;) The build quality seems good although I believe it would be very easy to bend key arms accidently (I found when adjusting C and Eb), so it needs to be handled with care.

The single real issue I have is that the front F key (aux F) does not work on my sax. The reason is that it doesn't close the B key completely. I cannot see any way that I can adjust it, as it does not seem large enough to do the job... so I have no choice but to use palm keys for high F, which when moving from C , for example is not that fast. For many starter players this may not be a concern. All in all very happy with it.