I would go ahead and paint them. Strip the paint off the painted ones, clean up the castings and prime them in a light grey primer ( the Tamiya aerosol primer is good) and have some fun with the paintbrush and researching the uniforms.
Do they have any value? I imagine not a lot. I have a small collection of the larger 54mm and 75mm Hinchliffe kits from certain eras that I will build when I get time. There are collectors buying those figures/kits, but not a lot of them, and there is an element of nostalgia driving those purchases. Certainly in the 1970s and 1980s Hinchliffe were very popular and had a good range with some excellent sculptors working for them. If you search Hinchliffe on this forum you will find a few threads about them. Hinchliffe were very big in the wargames figures market in the 1970s and 1980s.
There are a lot of good videos on youtube about painting methods for wargames figures, which has changed a lot over the years. Have a look through them and don't be afraid to ask questions here or post pictures of your work.
Scott
