The sound chip in the diesel is Massoth Giz as recommended by Mr Duffy. Works a treat on antilog, although it does need quite a bit of power and the track has to be spotless for reliable operation.
Pugsy mate, the tarp is made from stuff called Solertex. It's what they use to skin model aircraft. One side is textured (hence the "tex" bit - don't try Solarfilm, it's not the same) and the other becomes sticky when you run an iron close to it, this also shrinks it a bit so the folds stay in place and it goes nice and tight

. You can get it in a range of colours, but it also takes paint nicely. I seem to remember doing a thread on it, but goodness knows where? Maybe back in GSM days?
The washing is all my own work, done while SWMBO took her mother out (not with a shotgun unfortunately). I haven't told her yet what I "expressed an interest in" the other night ........... but, needless to say, I'm going to need a LOT of brownie points

.