The lathe pictured has been retrofitted by a previous owner to convert it to a manual shift headstock. We had the same sort of modification done on a 25" x 96" LeBlond wide-bed lathe for the powerplant machine shop when I worked there. We wanted a good used LeBlond lathe but did not want the headaches of the Servoshift mechanism.
Yancey Machine Tool, of Portland, Oregon, had a good 25" x 96" LeBlond wide bed lathe, and did the conversion from Servo Shift to manual shift headstock as part of the sale.
The LeBlond headstock casting on that 25" lathe actually had 'bosses' cast in the headstock for the manual shift levers, but was built as a Servo Shift headstock by LeBlond. Chances are the 'square head' Regal headstock casting had the bosses cast on the inside of the headstock for manual shifting shafts.
The Servo Shift mechanism is great when it works and a mess to deal with when it doesn't. It is a cross between the workings of an old electromechanical pinball machine or juke box combined with 'fluidics' to do the actual shifting.
On this particular lathe, I'd open the headstock and see what the internals look like. There was quite a bit of mechanism and fluidics in the Servo Shift headstock that had to be removed. The shifter mechanism for the manual levers may have used some LeBlond parts and some shop-made. I'd take a good look inside the headstock at the internals and see if there are signs of crashed gearing and chewed-up clutch teeth from the Servo Shift not working properly. Otherwise, I'd have no problem with a 'conversion' to a manual shift headstock if properly done. Personally, I would not own a Servo Shift headstock lathe.
