I've not run across an Airflow trombone. Was there other information on the engraving besides "Airflow"?

Thanks for your replies. Unfortunately the horn is on an online auction and there is no ability to contact the seller ... and the photos provided are not particularly good. As it seems like a rarity (perhaps for the good , perhaps not) I might bid on it for the fun of it and if it does not go for too much, just take a chance. Having done a fair amount of online purchases I am running about 90% in having good luck and getting a playable horn - they always need a good cleaning, but usually have an acceptable slide afterwards after a bit of tweaking and shine up well - I am not convinced that slides in the 1910 - 1925 era were that good to begin with so I am not that fussy. My best buy (and favourite horn) is a gold-plated 1925 Martin Dansant, also got a 1916/17 Holton Special (like that one too), a 1912 York Professional and a 1915 York valve as well as some other assorted horns. I will let you know if I end up with the "Airflow" and if it presents other clues to its origin.

Till then!