Tom - All the descriptions I've checked for the 1/2 ton truck repop hub cap spring clips indicate they are made from "spring steel", the same as the original pieces (read that in basically every ad description from all our usual vendors).
The big problem for 3/4 and 1 ton truck owners being only the shorter 1/2 ton truck clips are being reproduced/offered.
Wheel hub cap spring clips for the AD 3/4 ton and 1 ton trucks are taller than the 1/2 ton pieces and are currently in the "unobtanium" category, unless you can scavange some from old/unusable 3/4 or 1 ton wheels.
Fellow 'Bolter "tesa" has an ad in the
Truck Parts Wanted forum that has some related information if your interested.
