Thats a very rare Tech applique khaki bar on blue twill chevron there DR.
The one's that I have not seen, the specialist applique bars style dates from 1936-1942.
With the overhaul of the Specialist to Tech Ranks about the same time as the applique were rescinded your one stands out.
I'm hoping there are specialist applique khaki chevrons out there, however I have not seen any
A very good pick up indeed.
Here are my ones.
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