After pulling off the front axle, I found the LH location to be badly worn but the RH one ok.
I made a shim out of tin and replaced the bushes with ones cut to size from the rear axle of a discarded steel base and now it's totally firmed up.
I'm just going to touch up the LH side with some paint and leave the mower patina.

Ahh, if only victa had kept producing the thumblatch catcher series, they would be in better shape today!