The plastic horse's head mafia strikes! That is innovative scratchbuilding......
More excellent model engineering here.
LOL. Cheers Nigel

Bit of time over the weekend meant I was able to push forward with the new nose. I added some sheet sides and top over the previous internal structure and sanded down so now I have a lovely smooth nose that just lacks a 'few' details

Be12b new nose 2, on Flickr
Mix of Miliput (white) and Mr Surfacer 500 (grey) was used to refine and get rid of any minor gaps at the joins and whilst that was drying I added a few wrinkles to the fabric sides at the rear of the fuselage. All the Be12b photo's that I've studied seem to show quite extensive wrinkling of these areas possibly because of their nocturnal flying or maybe they all had a really hard life. Anyway I thought I needed something there rather than just flat sides so I further refined my earlier subtle attempts using a Dremel with a round bur and then finished them with a bit with sandpaper.
You might also spot that the original position for the front cabane appears too far back; looking at photos it appears to be right on the join of the new cowl. I'm not entirely sure whether the new engine was heavier and thus needed a slight tweak in the upper wing position to retain the CofG or if the plan is wrong, the original kit isn't quite right or (more likely) a combination of all three. Anyway I'll address this later so the front strut position matches the photos.
Be12b new nose , on Flickr
Lastly I was worried about how I was going to create the staggered cooling scoops which are a prominent part of this ones cowl. Turns out after a few false starts that they weren't too difficult

Here's the first one I made once I'd sorted out a method that worked for me
Be12b vent prototype , on Flickr
I cut a strip of plastic card the width of the scoop and sanded off the corner on one long edge gradually creating the back taper of the scoop along the whole length of the strip. Next I trimmed and sanded this end of the strip to give one half of the curved back edge and blended the new curve in. When I was happy with this I cut it off to the appropriate length of the scoop and repeated the cutting/sanding to get the other side of the curved back edge (This was much easier to write than actually do and resulted in a few pinging off never to be found again)

All that was needed were three pairs of slightly differing lengths

Be12b vents 2 , on Flickr