Hi
Looking at doing this very project with the aim of creating the GWR 150 chocolate and cream 117, with similar components.
Initial thoughts are:
1. The weak point of the whole project as I see it is that the Dapol 121/122 really doesn't like being taken apart and is extremely fragile and frail.
The impression I've got is one false move and £100 goes down the drain..
If you're happy taking it apart and getting to go back together with all the lights and the motor working then fair enough.
When I do this, I'm tempted to leave the bogies on both vehicles and glue each vehicle into a cradle like device so that the bogies dangle below
but the body is clamped tight and can be worked on. I've found that the brass contacts which the bogies match up with, if you've removed the bogies
bend very easily out of true, at the least I would recommend protecting them in some way (sellotape?) or if you are confident in taking them off
and putting then back on, then at least it keeps them out of harm's way.
2. I would be tempted to sand down the sides on the Dapol bodyshells and glue the side etches over them,
and also paint them before gluing them on (and re-use what Dapol glazing you can). The handrail at the front would hide the join and mask the slight overlap.
3. The 121 cab cuts off easily enough (I've dissected a non-power 122). The cab end fits nicely onto the Farish mark one, but the side height of the mark 1
is half to a full millimeter too high for the 1950's 116-119 style DMU's sides. Sand it down carefully and with the Worsley sides glued over it
would work fine.
4. You could even get away with using three Farish mark ones with the painted removed with brake/clutch fluid/Brasso, with the Worsley sides and the
Dapol ends glued on if things got tricky with the Dapol bodyshells. This would also solve the issue of glazing.
5. The Dapol roof fits the Farish mark one like a glove.The profile of the Dapol roofs seem different to the Farish ones.I think they can be adapted
but would need very careful sanding to do so.
I am only using Dapol roofs on the 116/117/119 DMU's I'm building even if I'm using Farish Mark ones as the centre trailers.
The 120 is going to be entirely Farish mark one based with BHE Ends and Electra Graphics vinyl sides.
6. I would recommend looking at purchasing a spare unpowered 122/121 as this would provide additional spare bodysides and also bespoke Dapol roofing
to the correct profile.
7. I am using my spare 122 bodyshell in the 117 project. I would cut around half an inch off, and cut a little off what would become the corridor end and
do a small cut and shut, just to get the body profile - gluing the sides over would remove the obvious join.I would use the Worsley Work Brass Inner Ends.
Might have to retain the the three sided buffer beam.Have you considered BH Enterprises as they sell the inner exhaust pipes and corridor connections?
7. The centre trailer - would work fine as a Farish Mark 1 with Worsley Sides, however, the Mark 1 roof needs work to match the Dapol profile.
I'm also looking at doing the 119 and 116 using the various dummy and powered 121/122's I've hidden behind the book cupboard but have yet to pluck up the courage!.
Wishing you the very best of luck with this one, and will watch your progress with interest.
Kind regards
Peter