You can powder coat the tail piece black. If you go that route with an older tailpiece, I'd seriously consider drilling the rear of the tailpiece for the two additional screws since the powder coat process may weaken the metal causing the tail piece to lift. The two extra screws were added by RIC on many of their powder coated black tail pieces to prevent lift.
I like the 4001 "hairpin " type truss rod more than the standard 4003 truss rods. Generally 4001's will cost you a little more so your platform may be more expensive to obtain. As far as better years for Rickenbackers, neck profiles are all over the place from year to year until they went to CNC manufacturing in and around 1996. I've played dozens of RIC basses of varying vintages and while I like some better than others, it's a subjective thing and like everything thing else that's mass produced, you have diamonds and lemons.
Vintage & exotic Rickenbacker basses
Orange Amplification & Glasstone cabinets