There seem to be designs out there. YES! There are hammer radio guys who elite theirs on 75 meters. In some ways such transmitters are easier to design than the ole mod transformer high level jobs.
But talk about anybody who has seen this as a potential for a little business (under ground). If they are there??
Years ago I almost bought a transistor 300 watt linear amp. The dude did have the units even built. Big issue here. If its a KIT and you are not a radio jolly rodger.. just want ham it.. well.. that legal. Built forget it dude. FCC demands type acceptance for virtually everything from CB to FM broadcast. I have a 300 watt, FM amp drives with 1 watt, BUt..... its not type accepted so using it in licensed broadcast service, just isn't possible. Tried to sell it quite a few times and of course the licensed stations can't use it so its value?? Zilch?
Now, a basic 250 watts class E for shortwave should be a piece of cake! Dude its NOT rocket science!!
But, nobody has surfaced, maybe for good reason, who supplies these things. Could Old Streachy do it someday? I have not a clue. Its up to I suppose basic economics.. can I do this legally? Well, yes you can.. its like guns.. you sell them, but its in how they are used.