Thanks Carpenter - yeh, have to say I was well happy with it when I got the second rad sorted last night, think it's worth the effort, especially as there's a wooden floor going under it. Budget overruns mean I have to do all the plumbing (except gas) in the extension: 3 rads and a kitchen, and thanks to the skills I've learned here (mainly from your good self) and elsewhere, it's not proving too much of a hassle.
Got my hands on chrome elbows this morning for the 3rd rad today, but have to say Viking House looks to be on the money with the wall plate elbows. [broken link removed] they don't seem too pricey online, but could be in bricks and mortar here. Will go with the chrome elbows for now, but defo will consider the wall plate elbows in the future.
By the way, I'll vouch for Viking House as an excellent and most helpful source of knowledge: I've seen many of his posts over on boards.ie (I'm FrankGrimes over there VikingHouse - the guy you gave the lime to for free. Worked a treat by the way, thanks again). He's a fountain of knowledge on all matters to do with sustainable building, particularly how to best build a house with excellent insulation.