"GAS" & "OIL" caps

[Steve Swan]

i have been keeping an eye open for the past 3 or 4 years with no luck for these "GAS" and "OIL" caps that fit the 1925-1929 J/JD tanks. i would like to have a pair that don't have any more dents that the ones in these pictures; of course no dents would be really nice!
gas cap.jpgoil cap.jpggas - oil caps.jpg
are these caps factory or an accessory manufactured by a non-factory manufacturer?