I just viewed your eBay listing for the first time today. Too bad you didn't ask for some help in composing it rather than resorting to anal extraction.
The Magnaflow muffler you've pictured on eBay is NOT for this header, it's for a system designed for a full-bodied car and ends up inside the RH fenderwell alongside/under the valvecover. No way it would ever even come close to working on the baja system. Nor is the A1 Thing Sidewinder system you've linked to comparable in any way to the item you're selling. Not in design, size, workmanship, or value. Yours was a ~$50 system (without muffler) in its day, designed to go on stock heaterboxes or slipjoint J-tubes.
There's no connection between the S&S of 30 years ago and the A1 of today other than the fact that they both chose the term "sidewinder" for their side-exit-flanged headers.
Your system uses a muffler that exits to the left side of the car - there's a 180° bend from the flange to the muffler inlet. Nothing like that has been available off-the-shelf for years, but it would be a simple enough matter to fabricate one (or have one made by a muffler shop).
I'd recommend you edit your eBay listing and delete all of the misleading information...this is how people get bad feedback.
For comparison, the "raw" baja headers on the market today (with upward-pointed flange, appropriate for a stinger) go for around $85. Another $60 buys a cheap chambered muffler for one. It'd take maybe $50 in materials to make a nice custom muffler for your setup, so the value's comparable. The main attraction of the sidewinder layout is that the exhaust is no longer in the way when you're trying to adjust the carburetor...plus it's cooler-looking IMO.
Hey Marc, thanks for your input. I agree and disagree. I felt I was trying to show the "style" which is similar, implying nothing else, pointed out the muffler went over cylinder not under apron and tried to cover the "misleading" with reference only. I agree about the muffler, could be misleading, again was trying to show style. I took your advise and ended the auction. I wasnt totally comfortable using other peoples pics in the auction anyway. I dont want anything to do with "anal extraction" so any help listing this piece would be welcome.