Bear in mind there are two types of connecting rod retention fittings and four types of connecting rod fittings.
The original Bulleid coupling rod is a depressed dished cover over, this is what the Finney7 castings represent.....kind of.
All leading axles have this type of fitting.
The other fitting is a washer with nut and cotter pin, this came along when the engines were rebuilt and a quick check shows all rebuilds have this type of fitting, however, it appears they modified more wheels than engines rebuilt so it is possible to see a BR crank pin fitted wheel on the rear axle of original engines.
Both engines also have the BR type of fitting on the driving axle, a domed cover and four bolts, on BR rebuilds these four bolts hold the return crank, on originals a simple cover suffices.
You need to check your engine and date and then find out which retaining fittings it had at that time and they do vary a lot across the class.
One other aspect on the rear axle, the LH side also has four studs to hold the speedo crank, despite whatever fitting is on the RH side.
In this instance (34066) and our date line had SR - BR - SR fittings and I don't have an indexing table so not quite sure yet how to replicate the four studs on the BR axle, mind I do have an XY table so that might work. More as likely I'll get some etches done on the side of another sheet and then fit them later as I doubt the model will be back here for final checks for several months.