One could order Attendant's Hats from most of the Oil Company's they worked for...
Depending on the Company; many allowed Employees to place a Company patch on a "Service Hat" that came close to what the Company was issuing/selling...
After WWII and later Korea; most Company's allowed Employees that served overseas. To use their "Garrison Caps" with the Company patch on it.
As to sewing vs gluing... I've seen patches attached to Hats and Caps both ways... By, the mid 1960s; a good number of Company's dropped full uniforms most notably Hats and Caps...
Not sure I have been any help.
