Carb and Divorced Choke issue

Welcome on the board. Your carburetor is a Holley model 1945. You haven't found the type number yet; the numbers you've found are casting numbers that don't help identify the carburetor. If your Valiant has its original carburetor, you are looking for a stamping on the carburetor body that says R6724A, R6938A, or R7096A. It is likely at this late date (37 years after the car was built) that its carburetor has been replaced, so you may find a different number -- many different type numbers are functionally interchangeable -- but it will be in that format: R1234A (or -AA, or -B). Often the type number is preceded by the word "LIST", but not always. Carburetor operation and repair manuals and links to training movies and carb repair threads are posted here for free download.

The original choke thermostats are getting hard to find, but aren't yet impossible. If you insist on it coming in a Chrysler box, you are going to have to go shopping at vendors of NOS (New Old Stock) parts, and the price will be high. You're wise to want to avoid cheap foreign garbage, but fact is there were not many sources for these; most vendors bought them from Holley and merely boxed and marketed them. For example, the last choke thermostat I bought for my '73 came in a Carter box, but was made by Holley complete with the Holley trademark and part number stamped right on it. You can get the original type choke thermostat by going on www.rockauto.com and doing a part number search for CT162 , which will be an American-made unit, almost certainly by Holley, and come in a Kem box. Or you can replace the non-adjustable original choke thermostat with a fully-adjustable, American-made Electric choke kit number 1234.