Following on from what Kris said, I'd get a reliable drawing of the class and check the various dimensions of the casting. No criticism of BH - but all w/m casting is dimensionally questionable as you can get shrinkage within the moulding process ,which manufacturers compensate-for by adding a little to the master! You may find room for losing the required length there - and end up with a more accurate model. The critical point will be lining up the smoke box/steam chest in relation to the cylinders. Can I say tho' that it's a brave move slicing up one of the best-looking RTR 'N gauge' loco's on the market (or is yours one of the early batch??

With regard to the A4, I take it that the boiler is whitemetal?? If so, you'd probably get a better strip with 'Nitromors' and a toothbrush.

The 'Mink C' body looks good (remember it is 'N' guage) - but I've always felt that the chassis (GF?) lets it down - it just looks too chunky. Try thinning the brake operating mechs etc with a scalpel blade. You just need to reduce the cross-section somewhat. Also bear in mind that if modelling the GW period, the u/f was 'freight grey' also.

Regs

Ian (ex 'N' gauge modeller!)

To answer a few questions.

The A4 body... it's a Graham Farish body and... I know whitemetal covers a wide range of metals, but this doesn't feel like any whitemetal I've ever seen in kits. It's more... solid. But yes, thanks for the stripping tip. I had to take the cast handrails off, and the pipe that was down the left side, so it made a certain amount of sense to scrape it. (Since I was scraping it already to get the bits off)

With regard to diagrams... I'm probably going to have to find a good book. There aren't any on t'interweb, or if there are, I can't find them. (The usual suspects don't have them). The RCTS loco books... only have diagrams of locos that weren't. Although they do have a good set of dimensions. (As, indeed, do the usual suspects.) The only question that remains is whether the length given for the boiler does, or as I suspect, does not, include the smokebox.

Oh, and I'm not brave. Just foolish.

Seriously, the change from Manor to Grange seemed like... one of the simpler options that I knew about at the time. Now, I'd consider possibly the B17 to B2 conversion as well. (Using the B17 chassis and the Langley B2 body. In reality, probably just the boiler).

Likewise, I can see quite a few possibilities for the Farish 3MT tank chassis... (Even, possibly, taking two of them to put under the Langley LMS Garratt kit). Or turning the Dapol 9F into the 2-10-2T that the GWR didn't build... but I'm rambling again...