I'm not sure of all the models that were made, but I'm in the market for one of these old bakelite beauties that is in excellent working condition. I'll be using it primarily for black & white, but would like to have the option of color. I think that this means I'm looking for an RT or the 'Color Densitometer' model. I'd be interested in hearing about Model 1's as well. I'd like to pay somewhere in the $30 range (+/-), including shipping. I'd be willing to pay more for a spectacular example with extra's, etc. Anyways, let me know what you have and we'll work something out. Thanks!