Yes, if I were you I’d do as much as you can yourself, then you’ll know the ins and outs.
I’ve restored and rebuilt several Brit bikes and pre 1970 cars, but having no engineering equipment (or skills) I had to trust a local and well respected professional motor engineering firm for rebores, regrinds, etc. and then assembled myself.
I also agree with some of the others, keep it basically original but there are some sensible modifications worth considering - all discussed in detail on here.
In my opinion these are: External oil filter in oil return. DVR2 voltage regulator, LED bulbs (except headlight), inline fuses as appropriate and if needed SRM 4-spring clutch and cush drive nut. To make maintenance a little easier an SRM sump filter with its magnetic drain plug.
My own GF was already fitted with Eddie Dow fork dampeners, SRM belt drive for dynamo and converted to 12v (but keeping the original 6v dynamo) by p.o. and I’ve carried out the mods mentioned above and also indicators after fitting a sidecar.
Rog.