Being 29 I can make a quick comment. I am predominantly diesel era, but that doesn't stop me having steam models, but they are mainly maiine locos and I enjoy the kit building side. I think the with the price of the hobby in 7mm and with more kit building/ modifying required may put people off and also with the diesel era has very little competion which doesn't help pricing etc like they do in n gauge and oo gauge, not to mention the lack of diesel prototype kits is lacking in the market with only one supplier for most of these but with a lot of the kits remaining the same for many years with no modifications or upgrades. Whilst this model isn't more me, I always commend and wish people well for producing lovely models.. You never know, a preserved railway scene with a little industrial loco may appear on a layout I will one day actually build.
Hope the venture works very well and all the best.
Regards
Edd