Hi Steve, do you have any links to the UK regulations on this? From a quick Google I came across this new Radio Equipment Directive at conformance.co.uk which says it will come in to force on the 13th June 2016, and says things like
"The Directive represents a further liberalisation of the requirements for telecom products"
and
"Custom built evaluation kits destined for professionals to be used solely at research and development facilities for such purposes is explicitly excluded"
Call my loft workshop an R&D facility and it should be fine?