Thanks for the update. The rego records have produced some amazing info: a few years ago we didn't know that Simplex motorcycles existed, now we know dates, the different models, the number of each and whether the engine was changed! Wow.
Pity we don't have a single photo or illustration of a Simplex, but we do know that all had Villiers engines, and most or all had Burman gearbox. "Twin port" was often stated - do we think that the 148cc engines used would have been twin port, or the cheaper single port? Tempting to think they were "Excelsior-esque", perhaps mirroring the Waratahs sent to P&R Williams in NSW.
We also know that the 125, 148, 196 and 250 models were all available "elec." (presumably lights powered from the Villiers flywheel), while there were also "De Luxe" versions of the 148 and 250. My guess would be these had real lights powered by a separate generator and a lead-acid battery?
Just so you know, I snip info that were share here and paste it into a file (in this case "simplex.txt") that goes into the simplex folder - one of 600+ folders in the australian bikes folder. In a typical folder there might also be 5-10-20 articles snipped from the newspapers, as well as any photos, catalogues, etc. This now amounts to a truly prodigious amount of info!!
Cheers
Leon