I know the time effort you put into restoring this airbrush and at least one other, to be honest if i was in a position to buy it which I'm afraid I'm not at the moment I would have happily have paid in excess of £100 for it and paid for the postage myself just for ornamental purposes, due to the work and indeed research that went into getting it back to it's original state I would urge you not to accept anything less.
Like me, there will be others who will respect your effort and dedication, while I'm not saying you won't be able to sell it here, you are limited in respect to the size of audience it will generate here, it would be wise to place it on ebay, and/or if you have a face book account place it there and ask for offers, but since you went to a lot of trouble to make it what it is, be sure to state clearly what it was like when you got and what you did to get it restored and working, the more you tell, the more respect it will generate, and don't put it up for just just bidding, put it up at a starting price you would be happy to let it go at and ask for offers above that, what you've done with this is amazing and a great advertisement for Badger, they themselves would be proud to know that someone had enough respect for one of their brushes to totally refit it.
As far as I know I am out of work now until next April at the earliest, I may get a day here and there but it wouldn't be enough to be able to buy this, but if you still have it around that time or even a little closer to May next year, I will take it off of you if it hasn't gone by then, so don't accept ridiculous, even if the brush itself was worthless (and it isn't), your hard work and time isn't, I did say (in excess) of £100, but I won't state the actual offer here because that is no one else's business, but rest assured it isn't going anywhere for less than £1oo, I'm not desperate to have it, so if you are not actually desperate to get rid of it or need the money quickly, you can put it up for sale as I suggested, and then if there is no other offer exceeding mine you at least know you have sold, and rest assured I will not be offended if someone else snaps it up in the time in between as long as you get an honest price that reflects your efforts.
I'll PM you with my exact offer