For the most part the older models are the hardest to work on. P38 and P47 in particular have some aspects of the model that make changing some parts of the artwork very difficult.
Hopefully, and as HTC is begining to do, the older models will recieve a revision like the spits did a couple of releases ago and like the P51 is in 1.11. This will also make changing the artwork a much easier process. Until that time though the only option is to work around the model as it is. I wouldn't want them too and don't, expect them to revise all their models just to please us skinners.
I haven't seen any official comment on any of HTC models/skins apart from Supa's NO to having the cockpit opened on the SBD and Skuzzys 'No, old P51 skins will not work ith the new 1.11 P51'.
Gatso