Funnily enough I've just got a Sun (Worksop) Sniper Plus off this forum, paid the princely sum of £30! It seems to have all the correct period parts too, Weinmann centre pull brakes with the Sun branded hoods, Huret derailleur and shifter etc. Paints a bit rough mind, but the original transfers are still there.
Aparently if it's a Worksop one it's post '63 I think.. Sun was the poorer brother to Carlton & Raleigh I believe an owned by Raleigh at that time
The Sniper plus was 1 up from the most basic model, so nothing fancy
General concensus seems to be fit what parts you fancy and enjoy! Although the centre pull brakes should work really rather well IMO. An if you can get all the original bits working, thats what I'd do (am doing!)
You've got no worries about spoiling a priceless relic
*2008 Rock Lobster Team Tig SL, MTB.
*1956 Raleigh Superbe 3 Speed
*Mid '80s Dave Hinde SL Lo-Pro/TT.
*Mid '90s Menet SPRL "team bike" Neuron 7410 DA.
And a few project bikes.