Young Ed

That's not them. Those are 41-42 only. I usually see them as lower grill stainless. I'm after a set too. My next truck will be a 41

Looks like my 48 stuff and I think they used it for many years 

Found the old post on the 39-47 IO Group. 
 
 
 
The bumper is a 48-56 Ford stepside rear bumper. Part number 49-4950 primered bumper $99.95
. 

I think 37-39 bodies were the same. Emblems probably changed but the basic lid might interchange. You'd need Mopar parts books or a Hollander to know for sure

There is a little slot in the bottom of the knob. A small screwdriver in there will release the clip from the switch. Then you can unscrew the bezel and the switch will drop out the back.

I made mine with material from JoAnns. Basic grey and maroon. 

 
 

DCM has reproductions. Finding a used one won't be easy. 

That is called the weep hole. It's supposed to be there. Just leave it. If/when the pump dies that's where it will leak. The plug supplied goes in either of those two holes for whichever doesn't match your heater hose setup. Your 52 should use the one you currently have plugged and the other output should be plugged. 

https://dcmclassics.com/
 

I'd that that mopar one is late 30s maybe prewar 40s. The other one is aftermarket. 

If you over tighten the spring it will be very hard or impossible to open. Could also result in breaking as PA mentioned. That spring provides tension to hold it open when out in the wind but you have to find the right balance.

As the mounts got worn the linkage was probably adjusted to compensate. Time to readjust.

For the 39-47s the first 2 digits are the year the cab design started(so all 41-47 cab tags start with 41) the next 2 are the cab type. So 12 is probably a closed cab and there should be diff codes or cowl and chassis, or panel trucks etc. The numbers after the dash are a production or serial #.

Everything but the radio stuff should be available at any auto parts store rockauto or the old mopar vendors like Bernbaum and Roberts. You should consider having your brake parts sleeved. I use www.brakeplace.com but there are others.

Any 46-48 and early first series 49 will fit. I don't know if they interchange to other models. There are also 2 styles. One has 2 individual brackets and one is one large one that is connected just behind the bumper.

The clutches are possibly similar although a car may have a smaller diameter setup. The bellhousings are the same pattern to bolt to the flathead and completely different after that. The truck bellhousing is much bigger and also contains the pedal setup.

Do you have this cross over pipe?

I believe this is what you need. On my car I just transfered the guts over to the OEM housing.