dm, I looked hard and long for the right bearing shells and in the end I bought 10 of what I could get and checked them against the actual measured journal diameters and the crankcase code and they were OK. I put them in, tightened them up and the engine tuns fine with no detectable play. The advice I was given was that it just isn't critical. You just can't get the exact ones that you need anyway.
I'll run mine in carefully with running in oil and whilst theoretically they may be tight I don't believe they are and running in will do what it says on the can.