Thanks for enquiring, I shall look forward to that release. I live in hope that OKB will do the tracks sometime, they do the Valentine wheels and a very nice Matilda set of tracks (I did think of trying to use these, but they are not really the right look). If they did the tracks it would be a big help, but I suppose that there wouldn't be a great deal of demand for them really.
The Milicast model is 1/76 which is the only problem, if it was 1/72 it would be perfect in some respects. Still it is a good stopgap while we wait for one in plastic and a bigger scale.
The searchlight bracket comes with the upgrade set, the lamp is a piece of sprue carved and sanded to shape with a spare PE cover and some scrap PE for the handle. There is a convenient hole in the bracket (approx. 0.4mm), so I drilled the lamp and put a small piece of wire in to fix it to the bracket. Hope that is a help for you.
All the best,