I used to attend the model enginer club in Chichester and know of at least one member who also belongs to Chichester model boat club. It is a lovely area and wish I had been interested in model boats earlier.
I hope that trends change in the future. I have experienced that children are more history savvy due to World of tanks and warplanes etc than they used to be, so there is a little hope. Scratch building in many fields of Model making have been affected thus, and by the plethora of after market parts, etch, and in recent years improved kits that now do not need the after market sets!
Also, I think model engineering subjects such as hand built model cars in metal, or even miniature internal combustion engines do not recoup the hours spent building them. A fellow member of said society reckoned that a miniature radial engine his friend built should be worth £37'000, but would get perhaps a fraction of that.