The wheels on your cool looking Polara look like the 80s Chrysler M-body (Gran Fury/Diplomat/LeBaron/Fifth Avenue) 15"x7" steel wheel (#4126675). They could also be found on some R-bodies. That wheel will accommodate up to the 3" deep Chrysler trim ring. The 2" trim ring already mentioned will fit but looks shallow on the 15x7" wheel and looks better on a 15x6" wheel. The 2.5" deep trim ring used on the 1972-1976 15"x6.5" Rallye wheels fits well. The 3" trim ring used on the 1970-1971 B- and E-body 15"x7" Rallye Wheels and the 1970 Challenger T/A standard 15x7 black steel wheels (Rallye was optional) (#2944450) will fit, but in some cases might rub on the center, depending on the stamping. The 3" trim ring was polished for 1970 and brushed for some late production 1970 and 1971 models.
The 15"x7" Police wheels (#3766077) used from 1978-1988 on B-bodies, F-bodies, and M-bodies, and shown on the gold Fury, are dimensionally the same as the 15"x7" M-body wheels and will accept the trim rings and hub caps. The Police wheels are built heavier with cooling slots and the center is full perimeter welded to the rim.
As also mentioned, Magnum GT wheels are 15"x7" and look like Police wheels without the hub cap nubs. Here is a Magnum GT wheel on my Challenger T/A with the 2.5" trim ring. These 2.5" trim rings would fit similarly on your 15x7 wheels.
Here is a 15"x8" Super Coupe wheel that I have on the back, which are the same, just wider. It also has a 2.5" ring which leaves a bigger gap. A deeper ring would match better, but I kind of like the way these look, plus it's what I had on hand.
I custom painted these wheels with hand flaking and added a 1970-71 cap (also painted the same). The paint is over done, but this car is not original itself (it also has a 440 Six Pack rather than its original 340 Six Pak. Stripes are to be added.). This is the wheels on the car:
For comparison to the 2.5" ring depth (and to get in another car picture), the 3" deep ring can be seen on these 15"x7" Rallye wheels on my other T/A:
Sadly, I don't have a C-body yet, so I have to make do with these smaller cars plus a few others....
NOTE: The foregoing information is only for Chrysler original trim rings and proper reproductions. Aftermarket trim rings can fit but may be different.