Technical nuances of Julius Altrichter (Frankfurt) Alto Tuba — 0.300 markings

[Baltic_Vintage_Vault]

Hello everyone,

I am currently documenting a vintage Altrichter Frankfurt (Oder) Alto Tuba (Alt-Tuba). It is a remarkable piece of German brass history.

I’ve uploaded detailed photos of the rotary valves and the 0.300 markings here to help with identification:
https://miraculousmatviishop.etsy.com/l ... -frankfurt

I have a specific question regarding the leadpipe taper and the 0.300 stamp on these Altrichter models. In your experience, how does the intonation of these Frankfurt-made altos compare to contemporary Alexander or Kruspe models?

I want to make sure my technical description is as accurate as possible for the community and potential future owners. Any insights on the valve configuration would be greatly appreciated.

Best regards,
Oleh (Baltic_Vintage_Vault)