If the Garand is in VCR colours, basically the entire rainbow, no problem . If it is in authentic coulours, then you'd be committinmg an offencer importing it, let alone displaying it. Unless you are an exempt person. which for us is 'A memeber of a recognised re-eanctment group, with Public liability'. Mind you no one says how many people need to be in a group, or who 'Recognises' them. You'll ned to show a photographic memebrship card that hs the public liability insurance number on it to any legitamite dealear, Main company for insurance is Hiscox Insurance. Though I did see for sale at the boot market at Finmere airfeild some soft air guns that would have been very questionable on the coulouring, no questions asked just cash.
A de-ac Garand, cash please, just check the right proof marks are on the weapon, the certtificate is aditional.