I have one of the Union Mills ex-LNWR Cauliflowers that I would like to take back to LNWR condition by getting rid of the Belpaire firebox. My metal working skills are zilch although I have a vice and files laid in.
I was wondering if anyone else has done this to one of these models or to the Midland 2F which looks to be a similar proposition.
Any suggestions / help welcome.

Not tried "de-Belpaireing", the nearest work of that sort on a UM model was changing a UM T9  from wide cab to narrow cab which I was able to do by milling about 0.5mm off each side. Files would work OK on the top corners and edges, but I would suggest that elsewhere files might be a bit awkward to say the least, the footplate and cab will make getting a decent stroke well nigh impossible for some of the work;

I would be inclined to work with burrs, cutting discs and other abrasive tools in a minidrill.

Are Union Mills' loco bodies made from a similar type of hard zinc alloy (mazak) to old Farish ones? The latter is really hard to work with, even removing surface detail like handrails is a pain!
This is something I've always wondered about, I don't have anything from UM (yet) and have no intentions of doing any major conversions on one, but it would be useful to know how easy it is to replace the moulded handrails etc.