A number of B-series plates were made in Arkansas.   Notice the different "B" die on the plates below - the Arkansas "B" does not have serifs.
BBB-991 has *both* types of B dies. The origin of this plate is unknown.

There is another series of Arkansas 'B' plates starting between BES and BEX, and extending through the rest of the BE, BF, BG, BH, BI, and some BJ prefixes.

Somewhere between BJA and BJL, production returned to New Jersey.   The different 'B' die without serifs was not seen after this.

Somewhere between EIX and EUI, the die for the letter I changed, and the serifs got much shorter.

As of RIA-100, experimental reflectorized plates were issued.   They continued until SZZ-999.

Starting with UAA-100, reflectorization stopped, and standard painted plates started again.

It's worth noting that the 1971/1972 plates has problems with the paint on the borders.
Usually, the top and bottom borders lose all or part of their paint, giving the effect of silver bars on the top and bottom of the plates.

The "Z" series was not used here - it was originally reserved for COMMERCIAL plates.
(We'll see the missing Z series later - on the blue base in 1985.)