I made the MISTAKE of searching long & hard for REPLACEMENT seat cushions. Very SS @ $400 with shipping. I since went to a local 'custom' shop that also offers auto upholstery repair & they quoted $150 max. to repair the only panel that was worn. Because the drivers back cushion was so difficult to find, I bought 1yd of the replacement fabric for any future 'panel' repairs for $70. I would suggest the same.
2004.5 3500 SRW,4x4,QC,SB: MBRP 4" Exh, Banks Tuner & Exh Brake, PullRite SuprGlide hitch, KORE lift w/Bilstein shks, MaxBrake, AirLift bags, Derale Trans Clr, Carli BJ's, 48RE Built-up w/"Precision" 3D TC, 233K miles.
Pulling: '05 HitchHiker II, 32.4 UKTG, 5th wheel = 21,300# GCVW.