Help decoding the fender tag on my LP27D7

Just figured out the 215 on mine and the 284 on yours

21 describes the tire 6.95 x14 BSW
28 is D70X14 red streak

The last digit is how many tired.

5 is 5 tires
4 is 4 tires

So

215 is 5x 6.95 x 14 BSW
284 is 4x D70x14 read streak (required on AC convertibles)