And it was an AMC crank they sorted for me A10Boy . . . you're absolutely right about that centre bearing - different size from the ends and VERY narrow, so not many people want to do them. They're pretty much the same on all the twins, except the 650s are even harder cos of the longer stroke. Plus, the radii are mega-critical . . . lose them, and BANG indeed (which has happened to me along with a few thousand others over the years). When I was in there, T and L had all manner of vintage car engines in; they have made special tooling for re-cutting non-detachable head 4 valve per cylinder 3 litre vintage Bentley valve seats - a loooong way up the hole, they have a dynamic crank balancer to die for, and on top of all that they are inexpensive and friendly. And they redo white metal bearings as well. They make their living on commercials etc etc, but they like bikes and have a few Santa Pod customers for whom they fettle cranks and so on. All extremely interesting stuff. They did my crank same day by prior appointment, plus sorted out some new fasteners for the rods (which are also a bit special on AMC twins) and gave me a tour of the works. By any standards they are GOOD.