A valid point, Larry. although I'm not sure what the alternatives are in 4 mm scale as I'm not aware of any higher quality body for a B1.
I hope Peter is right about the up-grades and really it will only be the basic structures of the boiler, footplate and cab that remain - and they are pretty accurate for an elderly RTR product.
I used to help Ray Hammond operate Thursford at exhibitions and he had a B1 with the same genisis, built by John Hayes, and it looked superb. Ray had an intrinsic dislike of plastic bodied locos but had to admit that you could only see the paint and couldn't tell what material was underneath. Thick edges would be a give away, but I've tried to thin down those round the cab windows and rear edge to disguise the true thickness, The tender will be a Bradwell etched kit, so won't have that issue.
I feel confident the finished loco will look OK and, of course, it isn't intended to be a showcase model.
Dave.