Get the best Amiga parts you have and build one A1200 using those parts. Keep that one, there should be a way to explain your wife that it is impossible to part with your past: you don't sell off the kids if they take too much space :-)
Then, secretly, build yet another A1200 with the remaining best parts. This one should be for spares ;-). Have a talk with your brother and make the A1200 dis-appear to his home ;-). Make sure no 'prone to leakage parts' are in that system (batteries ...).
The remaining parts can be sold off on e-bay. You could even considder selling it up in parts as that seems to generate more money. Also, choose the eBay country with care! In Germany parts seem dirt-cheap whereas in the Netherlands gold is charged (and collected) for 10+ year old Amiga stuff.
Oh, and don't change wives :-) Just take her out on a good dinner in a nice, little restaurant and make her feel a princess ;-)
