Willie, I have hundreds (likely a lot more) of aircraft armor, and naval ship books in my collection ranging from profiles and Air Enthusiast to Hunnicutt's and Spielberger's tank books. Lots of Osprey as well. Not so much in the uniformology department, tho' - mostly Greek, Roman, and Medieval. Painting up the latest run of Napoleonic Pin-up Girls has forced me to spend some research time on the interweb.
Roger, that Tamiya Pzkpw IV/D is rather elderly - late 70s or early 80s, I think. Still a great kit, tho'. With a little scratch-building (sheet plastic and rivet heads), you can make the up-armored versions used North Africa and and the Eastern Front. If you want a more updated D, you'll have to go with Dragon/DML. Be warned - Dragon/DML is really into individual link tracks. There are others, but I haven't seen them, so no comment. Try Tamiya's Pzkpfw IV Ausf J (Early Production) or Ausf H kits if you want a long-gunned version. Great kit. Tamiya's 1/48th scale tanks are also very good.
Ah, reminiscing; brings a tear to me eye it does...
Glen