Great bike. You probably know that the 1976 frames are relatively rare since Raleigh was winding down production on the Mk IV and the bike boom was winding down too. Mine is an August 76 frame set and had lived a much harder life than yours did - but that means it was much loved and well ridden. Now that it has been 100% overhauled and tuned I'm really enjoying mine. Great ride. I go stare at it most every day and ride it several times per week.
How do you like the ride on yours. Post a ride report and more photos when you get time. Congrats and nice job!!