oh dear, are you any good at brazing?
Those steel pipes are easily modified, , if your quick with a hot torch you can do it without heating the rubber pipe,
Other than that wouldn't a brake pipe nipple fit with some copper pipe to rubber pipe and a jubilee clip??
I know there's many different thread sizes of the nipples there must be one that fits and you can choose the type of face you want, any local garage can help i'm sure?