I don’t know anything, but I think you might find wheels by looking for offset or backspacing first, and then worrying about bolt pattern. The Speedster guys are always getting their VW bolt patterns changed to fit Porsche or other (narrow) 5-bolt wheels. They say it’s not too expensive to do.
Our wheels are 15 x 5.5, with I think 2 3/4 inches backspace.
Since most of the wire wheels on the market today (Dayton; Truespoke) start at 15 x 6, I guess you need to squeeze more backspace in to keep them tucked ‘neath ye olde fenders.