RobF4U

I need some direction on were to find informtion on "landing gear door" mechanisms.
I have an TF F4U (1978 kit) and "old style Robart 90 degree retracts" (they look nothing like today's catelog retracts).
I need some ideas on types of mechanical, servo or non-servo mechanisms.
I will consider all, mechanical, air, electric, nuclear. Diagrams, plans, or pictures would help
I know some of the ducted fan guys use some fairly sophistocated stuff, I would consider any alternative.
Thank you in advance for any help or directions.
Robin