The OP may have the oldest 'camelback' drill on this 'board. From the information, his Prentice drill predates my Barnes drill by somewhere around 15 years. It is interesting to see the evolution of this type of drill press. As things progressed, many manufacturers of this type of drill shared a common basic design. In a parallel to it, when the round column drills with V belt drive came along, many manufacturers used that basic design. In looking at the evolution of the basic machine tools, this pattern of many manufacturers using a common basic design is evident. "Cone head" engine lathes were another example, and then geared-head radial drills and geared-head engine lathes followed. Possibly the last link in this chain is the cloning of the 'turret head' knee mill (aka "Bridgeport" design).
To have a machine tool survive with its tight and loose pulleys intact and nothing missing or broken/brazed is something remarkable. It is rare to find old machine tools in their original location in a 'time capsule'. Moving machine tools around, WWII scrap drives (where many un-used/obsolete/damaged machine tools went to the smelter), need for space in a building/change of usage, and the conversion of many lineshaft driven machine tools to electric motor drive all stack the odds heavily against finding something like the OP's or my own camelback drills intact. All too often, the older lineshaft driven drills are butchered with conversions to electric motor drive and V belts, if the machines survive at all.
The roster of camelback drill makers in the USA is a long one. If the camelback drills from the different manufacturers were stood in a row, gotten dusty over time and in bad light, from a distance they would all look much the same. Only by getting closer and seeing the differences in power quill feed, back gearing, and table elevating mechanisms would the different manufacturers designs become obvious. The camelback design was a good design for its time. Makers such as Cendy-Otto and Buffalo Forge built on the basic camelback design and morphed it into V-belt/motor driven drills with their camelback roots being obvious.
The fact that these old drills are still useful machine tools after over a century speaks volumes for a good basic design. I use the Cincinnati-Bickford 25" camelback drill in my garage to push drills thru structural steel, and once drilled a load of locomotive spring leaves with 1 1/4" holes. I was literally filling a wheelbarrow with the 'turnings' (long chips) from that job. The Barnes 20" camelback drill is out in my blacksmith shed, and, as I like to say, a person can never have enough machine tools. The rhythm of flat belting and the whir of lineshaft pulleys fanning the air always plays a soothing melody to me, taking me back to when I was a kid, and causing me to hum or sing with it. The slight squeal as flat belting is shifted from loose to tight pulleys is a sound that also takes me back well over 50 years, and a welcome sound as well. Preserving these old machine tools that are survivors, with their tight and loose pulleys intact, and using the tight/loose pulleys rather than throwing a switch on a motor is special. It takes a bit more work to make a countershaft to drive the tight and loose pulleys, and while it does not gain anything in terms of functionality of an old machine tools with its own motor drive, it keeps the old survivors intact.