Shame you were'nt younger as taking over an established (i'm guessing) outlet in the US would certainly get a foothold in the market over there.
I know it's wrong but having a base there would probably give you more credibility too as you could just say THAT company were launching a new revolutionary design (yours of course) but package it differently so they didn't cotton on that it was you....lol.
The thing is, is he going bust because of the lack of sales in nitrous full stop or are people over there actually realising that the US nitrous stuff is garbage and that yours is indeed the best on the market in which case you should be getting a bigger share anyway.
Never know, some big company may offer you a price you can't refuse and you can semi-retire and get paid a consultancy fee as well