While the collections posted for viewing in this thread are carefully restored (and very nice) groups shown by serious collectors, Hank, go to the Classified section of this museum and all your dreams will be realized (well, maybe or maybe not, but have a look).
Perusing this Museum does take some time, but it yields incredible info. Check out the Articles section and see what Katie Wasserman has to say about finding NiCd batteries for the various models, for instance. Or the Memories of users and the experiences they've had with their favorite machines. Learn more about calculating machines than you ever thought you could know, by way of Dave's incredibly complete historical surveys and tutorials... and then introduce yourself to collecting via the Prices and Variations feature here...
Your HP-15c (and even your ersatz 34c) qualify you to start a collection of your own. Read Dave's summary of how and where to start doing it. Come on in, the water's fine!
(P.S., you'll find a lot of HP out there IF you are looking. What you find in the Classifieds here are often the cream of the crop, as collectors tend to be picky. But your hometown may have estate sales, fellow collectors, sale papers, and so on-- keep a sharp eye out. Since rare calcs and their accessories are the "coin of the realm" amongst collectors, finding a good thing to trade with them for what you really want may become part of your strategy. In this way, you are helping ALL of us-- by sniffing out the undiscovered stuff we haven't laid eyes upon yet.
Happy hunting.