Good point - I thought about this just after I posted. It's a Norwood 05A (1st week of May) car.
Does anyone else have a mid to late build ’69 with the original RW defog, that may include the installation pad I've show above in this topic? If so, what is your build date?
Maybe someone has a late ’69 revision Chevrolet Dealer service parts book that may show the insulation pad and list a part number?
Since the blower was installed in the “body shell” in the Fisher Body Plant at Norwood, the “C50” Rear Window Defog contents are not shown in the Chevrolet Assembly Plant AIM. Only the dash switch is illustrated on page 193.