I've recently inherited a pair of JBL C50 S7R AND JBL C58 Equipment cabnet (1969 70ish) with a Shure Reel to Reel, Fisher 600 and a Gerrard TurnTable. Flawless Condition!! I have no idea what its worth.
Welcome to AK! A number of things are going to determine worth - location of where you are (realistic market unless shipping isn't too hard), condition, originality, condition, needs repair or work, condition, (did I mention condition?)
http://www.lansingheritage.org/html/jbl/specs/home-speakers/1973-c50-c60.htm
S7R = LE15A, PR15, LE85 components with the H71 horn and slant lenses that are bolted to the baffle.
The C50 is the Olympus cabinet with top overhang and wrap around fretwork grille.
The C50 S7R uses a LE15A woofer that uses a white-turned-yellow and stiff surround material called Lansaloy. It was great when new but stiffened after some years. Some people like them original but they won't sound very good because there will be little bass response from them. If the surrounds are intact, good, if cracked and broken (especially if you try to play them loud), then the value is decreased. If the surrounds are grey foam, then they've already been updated and replaced.
The PR15 passive radiator uses a pleated cloth surround and unless damaged, usually survives easily. The LE85 compression driver should still have the red JBL wax plugs over the screw holes in the back, indicating they've never been opened. Good and bad there - good for originality and the original aluminum diaphragms, bad because the original diaphragms will work harden over time and eventually crack if played long, loud enough. But they can be fixed with new titanium diaphragms (JBL OEM only, not aftermarket) if they don't sound right.
As for price, if the cabinets are in good condition, fretwork grilles in good shape without cracks or missing sections, and all drivers working, anywhere from $500 to $3000 depending on what market you're trying to sell to and if you will ship overseas.
As for the rest, The C58 equipment cabinet is a really nice piece for someone who has interest and the room. But its size makes it very hard to ship so the market is limited. We'd need the model number of the Garrard table to estimate worth. Same for the RTR.
The Fisher 600 looks like a very nice tube receiver, probably one of their last - condition and function will determine what that is worth, I don't have much experience with those so wait for others to chime in.
This comment will be important:
:worthless