If you want to balance your library to cover the Army, then I would recommend The Tank Factory by William Suttie. Not a projects book per se, but it does feature some of the AFV projects of the post-war period.
Actually good books on British armoured projects are hard to find. In the Images of War series the British Tanks: 1945 to the Present Day contains some of the prototypes, but its not a technical book as such.
Not sure what the advise on the naval side, Rebuilding the Royal Navy is a handy guide, its a small book but dense. Depends on your naval interests, I could recommend Norman Friedman's British Cruisers: Two World Wars and After and British Destroyers and Frigates: The Second World War and After, they cover the politics and technical side and present a good picture. But they are pricey and Friedman sometimes has to be taken with a pinch of salt, he does make errors in his research.
I haven't brought David Hobbs' British Aircraft Carrier or The British Carrier Strike Fleet as I don't think they add enough to what I already have on my bookshelves. The first book is a good technical overview though if you like carriers and haven't anything on the bookshelves already. The latter is probably good but I prersonally I don't like Hobb's political point-scoring style, he lambasts a lot of decisions and the politics. I just can't decide if that is the personal prejudice of his time in the service or backed up by documentary evidence. But its probably worth reading in conjunction with other works. I know its on your list already, but I just want to add that Hennessy is not a naval historian by trade, but The Silent Deep is an impressive book.
Aviation books is a massive area and I'm other could pitch in with dozens of ideas. Anything by Tony Buttler and Chris Gibson is probably right up your street for a mix of politics and technical.
One final book, if you are into built infrastructure, but sadly which you probably won't find easily since its years out of print, is an English heritage title Cold War: Building for Nuclear Confrontation 1946-1989 by Wayne Cocroft. Really good in airfields, development of ROTOR sites, US sites, bunkers, command bunkers, ROC posts, features Spadeadam and other missile and nuclear experimental sites.
