No response on C&V so I'll try here.
I have a Maillard Course freewheel from the 70s, in good shape, that never really spun well because the internal bearings were too tight. It seems like it needs another internal 'shim' and I've read that freewheels were occasionally shipped without the optimum number of shims. I don't want to give up on this freewheel, but the right shim is hard to find. In the photo below, the shims are at lower right. I measure inside diameter as 27mm and outside as 30mm.