Rewired Massey 65 Diesel Tractor today

1964 Utility model 65, UNDM serial prefix.
The headlights worked briefly, then the right light went out. I'll pull it to check for continuity. I'm betting its old and burnt out like me.
The rear work lamp works fine.
I did forget to install my 20 amp fuse for the lights.

My fuel gauge only goes to 1/4 and thats it. A visual check showed the tank nearly full. Whats up with that?
I'm going to pull the sender to check it, maybe tomorrow weather depending. The fuel tank senders are about $80 bucks a pop.
Temperature went to about 180 and held after warming up. That's with a 7 psi cap, I couldn't find a 10 psi cap locally.
I don't know what thermostat temp is supposed to be.

My tachometer/tractormeter does not work. Its new and so is the drive cable. The cable is not kinked anywhere. Part number 193167M91 with cable part number 506334M91. This bears investigation. Its a female square drive at the rear of the engine the cable fits in. I could see it with a flashlight. Something is not meshing as it should.
There is a little plastic bushing gewgaw in the tractormeter end of the cable. What does that thingy do, what is it for?

The one wire alternator works fine. On startup it comes up when the oil switch closes and holds about 2 amps to the discharge side at 14.7 volts. After run a little bit voltage comes down to 13.5 Vdc. Still shows a 2 amp discharge though. Could just be the gauge. Also I'm not sure of the battery condition, Its an old battery, original to the tractor from when ever. Amps deflect more to discharge when the lights are turned on.

Oil pressure started at 80 psi cold and after warm up came down to about 55 psi.
I'm going to get a digital tach reading at idle later while I'm fooling with the tractormeter.

Still got some bugs to work out, but its getting there.
Thanks to eveyone here for their help. What a knowledgeable group of people!

Try loosening the nut on the tach end a little. I had the same problem with a new tach and cable assembly on my 65 diesel and it started working so I put a fiber washer I had that would just fit inside the nut. Been working great ever since.

It's supposed to have a 7 psi radiator cap, sounds like it has a 180 degree thermostat also which is fine also.

Are you sure drive end of cable is the right size and not slipping in engine side? Had that once with an MF30B with AD3.152. On that one, the new, MF sourced connector/extension was a tad too small and would slip, so I
had machinist make one to size. The cable did not connect directly to engine drive side.

Tractormeter update
I fiddled with it, loosened both ends, lubed the drive cable, put it all back together and its now working. Indicated idle speed is about 450 rpm. I couldn't get a good reading with the digital tachometer to compare.
I'm not exactly sure what I did, but it worked whatever it was. I did avoid tightening down on the tractormeter end of the drive too much. I did leave the little plastic bushing gewgaw in place on the tractormeter end.

Right Front Headlight
It was in fact burnt out. No continuity. Ordered 2 more. Aside, I had to run a ground for each front headlight. I'll have an old spare. Not super critical, but I like stuff to work the way it was meant to work.
Now to find a dash lamp somewhere, probably the UK.
Oh, and I need to install the fuse for the lights.

Fuel gauge
I used a decade box to check the gauge. At 180-200 ohms it shows full and about 20 ohms reads empty.
The fuel sender is another matter. I could only get 180 ohm readings a couple times and it was very intermittent. I could get no readings at all with the float lowered (empty). That was with sender removed from tank. It appears at least the gauge and sender will match pretty closely ohm wise. It doesn't have to be dead nuts accurate, it just has to work reasonably well.
I did order a replacement fuel tank sender, $61.