Got them all out with a breaker bar, wire brushed them, greased them and reinstalled. Can’t find replacements locally.
I could not get a 12 mm x1.75 die on them so I assumed that they were 14 mm, but the parts books say 12 mm x 1.75 x 45 mm. Will check again tomorrow, may the one out and take it to Fastenall for a fit check.