Post-1902 Pre-1936 US Army Enlisted Dress Blue Uniform Question

[rathbonemuseum.com]

I am posting hoping to get a little more info on what would be the correct collar devices worn for a US Army enlisted tunic in the 1902 style but worn into the 1930s. Attached for reference is a pic of a cavalry sgt wearing a 1902 pattern blue uniform but in 1931. As such, the collar devices are being worn in the correct fashion but are definitely more modern than the early 20th c. styles usually worn with this pattern tunic.

 

My question is, if this was a US Army Air Corps tunic, what pattern of devices would be appropriate for that late 20s/early 30s period?

 

Cheers,

[patches]

Here's an extensive topic in discusing the uniform and insignia in question.

http://www.usmilitariaforum.com/forums/index.php?showtopic=132581&pid=999931&mode=threaded&start=