Grand Rapids Band Instrument co Helicon on Ebay

[Todd]

Hello
this is how the helicon is listed on ebay
Vtg.WWI era, Tuba ? USA GRAND RAPIDS BAND INST., Co. Brass, model 38896, RARE

I was wondering if anyone knows how to determine what key this horn is in. I guess its hard to determine the year because the records of this company was lost in a fire? or something along those lines. I read that these brand was made by the same people that made yorks and alot of people think they are almost exactly the same.

Im thinking its in bb based on the inner tube of the cirlce. It seems like eb or f horns dont have a complete inner tube.

Okay thanks for any thoughts...

[Todd]

Thanks for response...