Matching crankcases complete with bearings and seals.
There had been problems with the gear change (which was the main reason for breaking the engine) which turned out to be the kickstart return spring support had broken off. This has now been professionally TIG welded back in as shown in the third pic.
The 4GY has been ground off the engine number block but DVLA don't seem worried about engine numbers - especially if they aren't unique as per the earlier TTRs.