I have now started my first attempt at using the MMP etched interiors are they were intended, for new construction. Unsurprisingly perhaps I find it is a lot easier to use them this way. I would go so far as to say that instead of trying to retrofit them it's probably a better policy to sell your old wagons on Ebay (or here) and use the proceeds to fund new kits. It might cost a few bob along the way but it will save on frustration and produce (I strongly suspect) better models.

The first wagon kit I am building in this way is a Slaters Gloucester 7 plank which I hope to finish as a reasonable approximation of the GC wagon shown on p117 of LNER Wagons Volume 1 by Peter Tatlow. Yes, I know it says it's a Cravens-built job but it has all the Gloucester features to my eye, including at least one set of Gloucester axleboxes. Anyway I did say an approximation as it's intended for my layout as a working wagon, not York Museum.

The white diagonal stripe shown in the photo will not be represented as I believe that's a post-grouping feature, despite the livery.

My way of building Slaters' kits is to start with the ends, including the fitting of buffers and couplings. This avoids a lot of fiddling later, and possibly tears. The latest kits are much better than the old ones and feature such advances as lost wax buffer bodies. I had to ease two of these out with a reamer before the buffer shaft would enter them properly. I mention this because a beginner might be puzzled at this point, and maybe not even have the tool for the job. The coupling hooks are also lost wax (I think) and certainly more sturdy than the old etched ones that used to come with these kits. I am happy to use these whereas in days gone I might have chucked the etched jobs in the bin and substituted Premier Components 3 links, which are my default choice.

I stuck the etches to the interior of the wagon sides with Evostick, which is the glue MMP recommend for the job. Previously I used UHU, but I agree with MMP, Evostick is better. I think superglue would be a mistake and I doubt whether MEK would do the job at all. The etched floor is stuck to the plastic floor in the same way. Obviously everything has to be carefully lined up and positioned, but a dry fit suggests it will all go together nicely. No untidy trimming of these etches.

So far so good. Photos will follow, but I'm too lazy to take any tonight.