What a find - looks to be a pre-1951 DL-1, given the Bakelite dynohub. The real deal too, not the later 1960's-1970's production that just doesn't cut it. Check the Sturmey hubs for date codes. (EDIT: The GH8 probably won't have a date code).
That shifter looks mint too. I also see quite a bit of wartime-era blackout parts here, even though it's probably post-war parts bin leftovers given the chrome handlebar. I wouldn't much more than give it a mechanical servicing, tires, tubes, and a proper polishing with Meguiars
#7 and some wax (taking care around that original pinstriping, which may easily polish off). It'd look brand new.
Pretty sure it's missing the seatpost binder bolt (in this case, structural to the bike - note the bolt-on rear stays - and the rear chaincase cover. Otherwise, pretty perfect looking.
EDIT: I'd guess that this is a '45-48 built from wartime-era spares, given the mix of chrome and blackout bits. I'd also guess this frame may be pre-war spares, given the headbadge and chaincase transfer.
-Kurt
P.S.: I'd classify this as a candidate for
refurbishing, rather than a "restoration." To me, the latter has always implied a repaint - which, in this case, would be absolutely sacrilegious.