i think...you should..
I think you should write a book or at least do a magazine regarding swaps of different engines ,what to look out for,how to modify and more..
I saw quite a few cars with big American V8 engine and more in your neat and tidy shop. If i were as good as you and with all the facilities, i guess i may come out with a magazine regarding many swaps and wiring and you can sell the mag online too .. then you might have some money and freedom from some annoying customers..
So if they call you for any advice ,just tell them ' it's all in my book ,go buy it online, (Understanding Automotive Wiring by Jim,Vol1 ),80AU plus freight'...
So that you won't ever get headaches ... And i can buy and sell it to colleges in my country..