Tuxedo Park IV

Need some help here guys . Found a '64 Tuxedo Park mostly intact for sale and I'm trying to nail down some specifics. It has a four cylinder engine, three on the tree and a Warn OD. The VIN plate codes out as a July '64 build with an 8322 model number. It has a sub plate embossed with "CJ-5A" and the letter "M". Any thoughts on what the "M" indicates? Thinking about doing it all red if I buy it. Being as it is definitely factory red, is there a trim tag that denotes interior color? Is anybody reproducing correct '64 tops? In red?
Thanks,
Tim