Hi, J-Tiki!
Welcome to the site!
Nice car you have there. As far as your question, I do not think there are any records showing what color combos came with which interiors. There may be potential numbers showing how many JA5 color cars there were, but those numbers are hard to find. Some guys on this site may have those exterior color numbers, I have NO idea how they have all this info!
As far as white interiors, they are not common in general. If JA5 is the original color, as you have mentioned, the black interior is the more common color. I don't know if 1973 was the only year or if it was also offered in 1974. 1972 had Light Gunmetal Metallic.
For 1972, the Rallye Challengers had a VIN that started with JS (same as the 1970 and 1971 R/T Challengers) and in 1973 and 1974 all the Challengers had a VIN that started with JH (Including Rallye cars) but the cars with the Rallye option had A57 coded on their fender tag, which I realize you stated it is missing. for 1973 and 1974, Rallye was an option on all Challengers instead of a separate model in 1972 and R/T in prior years.
From what it looks like, you have the Rallye options. If 1973 is like 1972 (I'm more familiar with that year.), Rallye cars could come with a 318 or 340. You do have the Rallye gauge panel, front fender louvers and strobe stripes, blacked out grille/tailpanel. You'll probably have the Rallye suspension also.
Starting 1972, there were no factory wings installed, perhaps you could order one from the parts counter, I don't know. The one on your car is a 1971 Go-Wing, or "gull wing" style. Only 1971 offered this style wing.
You have what appears to be 15" rims. I do not think they were offered in 1973 but I could be wrong. The centercaps are 1971 style with the dark argent grey paint. 1972-1974 cars have a different center cap and I believe the Rallye rims were only in 14", in fact I think all the rims offered for those years were 14".
Curious thing is your hood has no D O D G E letters on the front. This was a 1971 thing as all the other years that I am aware of have the lettering, 1971 being the only exception.
The car sound great on the video! Has a mean nasty tone. I'm surprised they are Flowmasters, they sound a bit different. They have a more raspier sound than turbo mufflers, almost like glasspacks. I like it!
Feel free to hang out and ask lots of questions. Lots of nice people here with lots of knowledge of these cars!