1969 mercury 500 50hp Choke solenoid and tach wiring

Hey guys, i have 2 questions...

1. I took took out the choke solenoid last weekend and was doing some bench testing on it and i believe it is not working. i tested the wires going to the solenoid and its getting +13V but it is not actuating. Is there anyway to tear apart these old choke solenoids and repair them? its a metal housing and i dont believe i saw any screws to easily open it up but i should be able to tear it apart. i was loking online and could not find a replacement, the part number is 45068. i do not want to buy a used one off ebay that "worked when i pulled it from the boat". Are there any "aftermarket" choke solenoids that would work with the plunger style?

2. I also have a mercontrol unit with the 3 prong plug in the front of it and its supposed to be for a tachometer. once again i havnt been able to find a wiring harness for it thats not used on ebay and was wondering if there is anyway to solder connections to the prongs from a marine tach? Ive been reading up on them and there should be a ground, +12v and a sender signal.(from the stator?)

any help would be great! thanks!

No way to tear it apart.Only one wire to solenoid,the body is the ground.The metal plunger is in the solenoid when you test? It needs to be as the solenoid creates a magnetic field to work
You can use standard spades on the plug or solder whichever you prefer.The tach plug wires are,black = ground,white = 12v+,brown = tach signal.The harness can be got,here is a link to you motors' wiring http://www.maxrules.com/oldmercs/Wiring/1966ona/26A.jpg