Cheaper race/tourist bikes from thr 70s are often equipped with Simplex chainrings with a cover plate/chainguard that looks really bad and unpractical.
https://www.velobase.com/ViewComponen...m=122&AbsPos=2

The chainguard is probably made by Nervar. Style example:
https://cgi.ebay.com/111113751408


Do you remove it from the chainrings?

Much like the dork disk for the freewheel.

I haven't seen any cheap bikes with Simplex chainrings and adapters. They were high end in their day And they're expensive now.

Come to think of it, I've never seen a chain guard on Simplex rings.

I agree. I get a heck of a lot of bikes each year (not mine) but it is rare to find one with Simplex rings.

Do I remove chain guards? Yes, unless I am restoring a bike to original specs.

Strange I've only seen the plates on cheap bikes that mimics the look of race bikes. Heavy frames and cheap components and stands and integrated locks.

Yes there are other gentlemans bikes with chain guards etc, especially Brittish ones, that looks more exclusive. But they haven't got race geometry.

My point is that those cheap bikes did not have rings made by Simplex.

NOS Nervar ones go for $10 on ebay, used ones probably bring $0.

My basic rule on ebay, if I don't think the item will bring a minimum of $15 AFTER FEES!, I don't bother. Add up the time to create the listing, take pics, pack, label, and take to the post office, there just isn't anything left. We have started to sell groups of lower value items, gets us over the $15 mark. Depends on the hassle to pack, etc. If I had the crankset to go with that chain guard, sure, I would sell the item complete. I have a box of dork disks, chain guards, and kickstands that need to go.

I save usable, but lower value, parts, and include them in my quarterly co-op donation run. I'll try to remember to grab all of the kickstands and include them in my next donation.