greg bender
http://www.thisoldtractor.com/gtbender
This information was gleaned from Beedspeed.

| Code Number | Type | X value measured in hundredths of a millimeter. |
|---|---|---|
| 8540 x 28 | AB | 260-262-265-268-270-272-275 |
| 8979 x 28 | AF | 330-340-350-360 |
| 9593 x 28 | AR | 260-262-265-270 |