I've never seen it either, and can't find in the Light Trucks MPC. But the part number looks like it should be a heavy truck part as our covers are 1002108-A.
Yep:
80/ F600/800 - - w/o A/C E0TZ 6002108-A R.H.
83/ FT800/900 - - w/o A/C
Gary, AKA "Gary fellow":
Profile
Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow
Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker & 10.25 Sterling/Trutrac, Blue Top & Borgeson, & EEC-V MAF/SEFI