Yes, a Caledonian 4-4-0 would make a very appealing proposition but, as there were quite a few varieties, the question is, which one? A Drummond 4-4-0 would be nice but, as they were pretty much all gone by the early LMS days, they probably wouldn't generate enough sales, with the same being true of the earliest of the McIntosh 4-4-0s. The later McIntosh engines are more likely to sell well as models, having a wider application, but there is the problem of the tenders - they were built with bogie tenders but the LMS withdrew the bogie tenders and replaced them with a variety of six wheelers from withdrawn engines. To my mind if there were to be a model of a Caledonian 4-4-0, it would have to be a Pickersgill. There were two classes, 113 and 72, almost indistinguishable and they all survived from Caledonian days right into British Railways (with one accident victim excepted, almost to the end of steam) almost unaltered other than a few changes to boiler mountings. Possible liveries, Caledonian light blue and dark blue (they appeared in both), LMS red, lined black, plain black and every variation on British Railways black, lined and unlined.