Hi again.
Roger on the new razor. Mine isn't that old yet but definitely will be picking some spares at Warley. It's not really been critical for the most part though as bar the aforementioned ends i've been able to leave a decent amount of sacrificial width for error and then filing the edge back until happy. My mitre block is fine for most bodging but too slack for this job so instead have been using a small engineers square and resting it against the top and bottom edges of the compartment pending which end i'm attacking from.
I'm leaving the guard coaches for now as they look a bit ambitious for me and i'm still holding out hope Bachmann will (eventually) get round to enlarging their OO tooling but it's something I can always come back to.
I'm amazed you managed to get 5 compartments back in as i'm about a 1cm over length currently but that's fine as I don't mind the coach becoming a shade longer. This does mean the roof won't be reusable as it stands but again fine as I was planning to do my own thing due to not sticking to just the older four and five compartment prototypes.

I took your advice and recycled the ends for finishing the 3rd class beading and at the same time decided after a fashion to model a LBSC D73 (seen on p176 in LB&SCR CARRIAGES VOL 1). I'll glue, fill and prime this one up first as there's only a single joint to worry about and then return to the other with hopefully a little more know how. I'm not actually modelling the LBSC per say but i'll take you tip about GRS door handles when i'm filling out my next order from them

Regarding the compartment offer that would be nice but if you think the spares may be of future use for strengthening or for going toward another block set then absolutely no worries.
Cheers Mark