Per a recent conversation with VPI: The was an, "early" Mk II, frosted acrylic platter, and the, "later" acrylic/lead Mk II & III platter which you own. Regarding the springs, vs the pucks: Some prefer one over the other. The low cost allows for much experimentation(except for the MK IV springs). The spring tension/design DOES VARY GREATLY, between the various iterations of platter, and their weights. Buying a used platter can be risky, as the spindles/bearings can be easily damaged(there are a lot of clutzes out there). The steel and acrylic BOTH comprise what is called the, "chassis" of the HW19, and the heavier/the better(by a wide margin). Of course- the acrylic armboard is a separate entity, on all but the Jr(no steel) & Mk IV. I own the SDS, and they do make a huge difference in sound quality, providing your house voltage is not a stable 60Hz(mine wasn't), or- if your speed is off, for any reason. Good luck finding one at a price used, that allows any room(within your budget) for further mods. You can buy one new, at MSS Hi-Fi, for $995.00. Isolating the motor from the plinth(as with the SAMA), will cost you very little, if you can DIY. Of course the Denon 103R is a nice cartridge, IF your phonostage will support a .25mV moving coil's output, as opposed to your present 4.5mV, and allow for proper MC loading.