There's a member on hondatwins.net who had the same issue w/ the CB200 front brakes(like the same tank you have on yours) and found a swap from another make or model that'll do hydraulic onto the CB200..,which is basically the exact same front brake system that's on the CB125S.The guy's name is Steve,he's been offering the swap to lot's of hondatwins.net members for a couple years & if you needed I could get you his member name & you could PM him.
Bill