the issue is the cost and availability of quality repair parts. Take a look what a VRS gasket set for a 186 costs these days. Or a rebuild kit for a stromberg carby. Sure you can do the repair easily, but what are the punters willing to pay? I doubt there's any money to be made. Exact same issue as series landies - imagine trying to sell one here for what the North American Overland guys charge?
Earlier this year I picked up a few glass bowl fuel pumps and rebuilt one of them, including nickel plating and yellow passivate so it looks brand new. Cost me probably $150 of materials and took a full day - you'd have to charge about $600 to even make it worth your time. Who would pay for that?
