Got some new info. Model A Locators, such as the one that member ShortArc has is a 12 Volt nominal model with 4-direction gimbal, no fan in the lamp housing but with a fan in the base. Model B is the same but for use with 28 Volts. Model 300 is of the same vintage but is a multi component unit. A non-gimbaled light head, a remote control and a separate power supply. The power supply looks like the base of a Model A or B and comes in an "A" and "B" model for use with 12 and 28 Volts respectively. Then we move on to my original Locator model - the model 1242. It'll be fun to see the Model "B" that I have coming to me and make some comparisons.
ShortArc, I will email you a PDF of the Model A/B/300 operation and troubleshooting manual that I got from REACH Air Medical Services.