1977 Front brake caliper

Hi. New user - hope I’ve posted in the correct place.
I’m trying to rebuild my Asco brand front calipers. They are from a 1977 GS550. They have two ‘spindles’ in each caliper (Suzuki calls them ‘axle pins’) (part numbers 5930545020 and 5930645020) that allow the caliper body to slide along the mounting bracket when the brake is applied. They seem to be completely unobtainable - I’ve tried CSNL, ebay, Fowlers, Suzuki GB and Robinsons. My original pins might be usable if I get them rechromed but they are very corroded so would prefer to get new ones if possible. Does anyone have any ideas where else I could try?
Thanks
Regards
Tony