Time for a job I don't enjoy, soldering the washers on to the crank pins to hold the rods in place. It's one of those jobs where everything can go wrong, and you end up with a lump rather than a collection of moving parts.
My solution is to put permanent marker everywhere I don't want the solder to go. Since the stuff will only stick to clean metal, in theory (and practise I'm pleased to say) it won't stick to the penned up bits.
As an extra precaution, some light oil floods the crank pin hole in the rod. This is the old skool way of doing things, but I'm always concerned that the heat of the iron will boil off the liquid and let the solder do its worse.
Anyway, in the photo, you can see the true horror of the over-large holes in the rods, but as the chassis works fine, I don't care how much it annoys proper engineers, I'm not bushing them.
Another handy hind, ignore the washers provided with Romford crank pins, you only end up filing them much thinner, just use some 10BA brass washers and save some effort.