Having decided on a target loco (31 415 , MR then BS) http://www.rmweb.co.uk/community/index.php?/blog/296/entry-14486-a-decent-31-prototypes-and-problems/ and with an Airfix body in hand , what needs doing?
Firstly, remove the numbers and symbol with surgical spirit and a cotton bud. Next , a swift appraisal.
The Airfix model was state of the art in it's day, but that was 35 years ago. Still, many competent judges seem to rate the moulding highly in terms of basic shape
The body side steps and roof filler recess need removing. An etched fan grill to be fitted - A1 Models etch in stock. Nothing to be done to the main radiator grills. Flushglaze - SE Finecast pack in stock. Engine room pipe runs - I have a set of whitemetal castings in stock to use . These will sit behind the glazing and have to be done after glazing and therefore after painting. Cab door handrails are beyond me to replace neatly, so leave them.
Much of the work is on the cab front. Cab doors should be plated - I have an A1 Model etch available. The moulded inverted-L handrails are grim and must be replaced in wire , and a top handrail added. Replacing the lampirons is too ambitious.
The buffers are almost 2mm too short compared with a drawing. A1 oval buffers are between 0.5mm and 1mm too long but more substantial - a marked improvement even if not quite perfect. Once Kadees are in place on the chassis it will be possible to see whether any buffer beam pipework can be fitted.
As far as I'm aware, no significant modifications apply to the chassis . This was one of the better runners on my teenage layout - with a decoder fitted it runs quite nicely even if it growls a bit. It didn't see a lot of use so it's a virtually new mechanism
Airfix took the yellow right down the front to the bottom of the buffer beam. A few locos - I think on the WR - had this but normally the buffer beam was black and this substantially changes the look. Photos show a recess under the cab doors producing a notch in the bottom edge of the cab front. Airfix don't model this. All shots except very early ones show two little wings on the shoulders of the cab doors . They're quite noticeable - but Airfix omitted them and I don't see a way to model them neatly so they'll have to be omitted. Possibly windscreen wipers
There's no cab interior of any kind - some basic provision needs to be made
This little list does show why the Airfix 31 didn't really convince me from the front
And here's a shot of the bodyshell with work well under way
An A1 etched roof grill has been fitted (I think this is actually meant for the Lima 31 not the Airfix model) , and all the side steps and roof recess filled. The filler I have is not great stuff - it crumbles away at the slightest provocation leaving a pockmark - and I really need to invest in something better. For once the Milliput worked and set - evidently this time the stuff wasn't past it's working life - and was much better to sand down
The etches for plated doors are in place: these were quite difficult to get flush , or reasonably flush , over the underlying moulding despite my filing down.
The replacement handrails are on. It is surprisingly difficult to bend them up exactly alike on both sides despite using one of Bill Bedford's handrail jigs. I was rather nervous about this part having recently acquired a roughly modified second hand Airfix 31 for a spare chassis and seen how crude its replacement handrails were - but mine seem ok
The new buffers are in place - AI Railmatch oval brass buffers from the bits box . Possibly fractionally long - but a good deal better to my eye than the anemic Airfix efforts
The body has been sprayed in Rail blue with a Railmatch aerosol