details, pics, actual measurements???

which hub model? which SS freewheel? how deep is the threading on the two parts?

pushing it further inboard may make it harder to get a good chainline anyway, and that 3 or 4 mm extra distance off centre might be just the ticket..

and before we help you, you'll have to convince us that you've been nice to your bike and haven't lopped off any brazed on parts from a valuable old frame.