john is right they are fantastic straight suction canisters. one of the best. simple easy to maintain and use. i own 5. two penncrest and 3 hoover badged. far as aquiring them AVOID EBAY. they are way overpriced and 95% of the time, missing important things like the hose, tools or telescoping wands. either that or they have bojack hoses, torn hoses and mis matched tools for that specific model.
rare models include the 434 (white and canton red) green and seal griege 858 tilted connie, model 87 with electric hose (in jade green, same as model 67 convertible), penncrest A108 and penncrest A107 badged constellations, and the model 88 in fawn.
unfortantely, the tools colors dont always coincide with the cleaner, so asking more versed collectors such as myself, john long, fred stacknik or tom gasko to verify what attachment colors should go with a certain model.
far as finding a connie, your best bet is estate sales, thrift stores, flea markets, antique stores and other collectors here. ill keep an eye out for one. if i come across it and its one i already have, ill put you at the top of the list for one.
also they take j bags. get vintage ones. the new ones from hoover.com are not made as well and leak badly. vintage j bags will be light green in color and come in a pack of 4.