Looking through some Pre/Post AR serial number lists, I noticed that Sendra is listed with some post-ban numbers.

I'm still trying to understand how there can be post-ban Sendras (I'm talking date of manufacturer, not assembly.  I'm not concerned about some weird situation where a stripped 1986 lower sat in a drawer for 15 years.)

Jerry Drasen was convicted of a felony (selling unregistered SBRs) in 1988 and couldn't manufacture guns any more.  Since Sendra then went out of business, how can there be any post-ban Sendra receivers?  They all should have the same status as EA receivers.

I've seen references to the "circle" determining whether it's a pre or post, but I remember back in the '80s I could always spot a Sendra lower by the circle on the right side of the mag well. So as far I know, all Sendras have the circle and are prebans.

Did someone else beside Drasen manufacturer Sendra receivers after 1988 and through 1994?  Is there any documented (non-anecdotal) evidence of post-ban Sendras?

I'm not 100% positive, but I'm under the impression that ALL Sendra, Drasen, and Nesard receivers are from the same place, and are ALL preban.

I have two Sendra lower recievers, one is a Registered Reciever converted by Chesterfield Armamant and does not have the "circle" you described.  I also have a Sendra Semi lower with a lower serial number than my RR and it has an area machined on left side (muzzle forward) of the magwell area where the serial numbers and model number (XM15E2) are located.  This looks more like a "D", about 5/8 of an inch wide starting flush with the front of the mag well and finishing off in a half-circle in the rear as if a round surface type cutting type tool was used to make the mark, it is about 1/16 of an inch deep and runs the lenght of the mag well.