Tom -- I was impressed by your interior cover and ordered one shortly after returning to Boise. I'm almost certain mine is the same as yours, just a different color (red vs. grey?). I recall yours has a rather subtle "Front" labled across the windshield area, as does mine, and I believe they're from the same vendor.
Ron -- My 280SL also has headrests, and the interior cover fits just fine over them. Here's a link that'll take you to the vendor I used (Car Parts Discount):
http://216.60.144.111/ecatcust/getx.asp?custid=50580Go down the page to the 3rd item, which is "Specialty Covers" from "CoverCraft", then follow the "Select" prompts thru Interior Covers; Sunbrella; etc.
Tom in Boise
'71 280SL 4-spd, signal red w/lt. tan interior, restored/enhanced