Hi PD...Looks like your hub and wheel were just there to stop the mudguard dragging in the dirt on the day of purchase.
Well, here's the good news as I see it. That 49 tooth "dinner plate" sprocket and matching brake plate are from an earlier plunger framed bike. 49 is sidecar gearing. Solo is 42. They are no good to you, but saleable in the grand scheme of things. Your choice now depends on how your frame is set up for the rear brake pedal. Left hand rod, go with 1954/55 rear hub, you may need to add a torque arm mount, depends on what is left on your swinging arm. Hollow S/A spindle, choice is Ariel Hubs, rarer, only used for a short time, or later cast iron full width, both plus a rear wheel to suit. Crossover shaft, pedal, cable etc will add to the complexity and expense. lots of comment on brake pedal choices on the forum in recent weeks.
I reckon your present wheel will fit, maybe with just the correct spindle, plus the odd custom spacer, if you stick with the early half width S/A brake. Probably ended up with 49 teeth in a misguided attempt at scrambler gearing.
Swarfy.
Swarfy