Oh yeah, Ed, I didn't notice that! What a donkey!
@Craig - funny I'm not sure I'm going to keep the trades - the plan was to have a suppressor that disappeared into the RIS and looked like it was integral to the barrel, like an MP5 SD6. I've decided on a Tanio Koba Hop Twist inner barrel, because I want to keep it under 350FPS for CQB an pussy-sites, and get the best range & accuracy I can from that.
Ed is selling me his 509mm TK so I needed a 260mm x 40mm suppressor - this was the only one I could find in stock (my 1st choice was plain & intended for KWA Mac11 but probably no longer available). I spose the easy-grip surface gives it away as an aftermarket addition though, so maybe I will leave the trades - not sure of the paint job yet, but it will definitely be mainly, if not all, greys so perhaps they could stay without looking deliberately poseurish (ie arsewankingly cringeworthy) - I'd prefer it if that milled/etched/whatever surface either ended in line with the RIS, as you say, or better yet extended the whole way down, but that's life *sigh* - before/instead of paint I might try some kind of textured tape, bike handlebar grip tape maybe or even skateboard grip tape.
I don't mind the standard G36 foldible stock, but I wanted one that could fit a larger battery than you can get in the hand guard and, for it to be properly comfortable, I needed adjustable - it comes with 4 positions but I added 1 between the longest 2 and now it fits me perfectly. They way I've got that '4 point' sling attached means that when it hangs across my chest, even completely loose, raising it automatically puts the butt to my shoulder, raised a little more and it's in my natural firing position, without me having to deliberately shoulder the rifle.
That's another reason why I feel confident that the 551 will work well, because my shoulders are quite broad and my neck is quite long (judging by how much I need to bend it to use things designed for 'the norm') so my natural firing position puts my head higher up than someone who can easily rest their cheek against the stock. It may look a bit boxy, although I think that the K length RIS and 260mm suppressor, rather than C length & 220mm which I had first planned on, ameliorate that, but truth to tell I don't care.
My intention with this build has always been to design a NATO gun which would suit my body and skirmish style as exactly as possible first and only then consider the aesthetics. That's why I decided that the H&K intended red dot sight wouldn't work, because it has a very small window. The integral 3x sight is quite small too, but I can use it without having to lean my head forward so far that it's uncomfortable, but I do have to consciously position my head. I'm hoping that I'll be able to see through the 551 with my head exactly where my neck is most comfortable.
Thanks for the info on the EOLAD, Craig.
@Nickona - yeah, on "American Guns" or "Sons of Guns", I forget which is which - the Red Jacket shop, they had to fabricate a piccatinny rail mount for a modern Masterkey type project. I really hope that I don't have to build what I want completely - I don't currently have the 'kin tools, and though I want to replace them & get more, currently it's all about cash