Hello from Canada!
Building a Matchless G3L from scratch and cannot find any wheel building detail ( spoke pattern I can pretty much see in some pictures but; the wheel “off-set” is really needed for both wheels).
Thank you as always for any considerations of my request!
Bill if no one comes up with the offset measurements. You will have to set the wheels up in the frame so that the center of the rims are in line with the center of the bike (ie tank tube and center of the front forks). There is a 5/16" offset at the rear spindle. Ron