Bravo! 1D and 7D are ridiculously clever. I was very pleased to solve those. I'd also like to praise 3D and 4D... Wait actually the whole puzzle was just a delight :) thanks Bob!
Playing a very belated game of catch-up, or is it more that I just get to now enjoy a "daily" stream of Bob-isms? Really, really good stuff everywhere here.
Solutions: