Vintage BMW Motorcycle Owners

First, I am NOT very knowledgeable on these old bikes, I love the Pressed frames and have wanted one for many years.
I was wondering if anyone can pick apart this bike? Told by owners son it's a CJ750, but I've not seen a Ural or CJ with the pressed frame, only EMW.

Googleing around this is where I am at. I am thinking it's a bit of a custom built setup grafted together from 3 or more bikes.
Front end looks R12, forks and fender
Front of frame seems more R35 than R12, no rivets (?) Between logo and steer tube
Rear of frame is R71/CJ750 style, upper shock lugs are short vs R35, seat mount linkage style with near horizontal spring under seat attached to rear fender.
Rear fender looks like some adaptation of the R7, don't see any other models that have one like this
Motor is obviously a later airhead
Sidecar is likely CJ750.

Anyway, any insight?
Any value thoughts on it?
Thanks
Matt

The frame is a late EMW R35 from 1953/54. Made in East Germany. Note the red and white tank badge. The fenders are R12 Deco fenders. The motor appears to be early 70s /5. Can't tell about the forks from that photo.

ToasTwinCam Thank you for the reply and info.
The linkage seat and shock mount are what throws me off comparing it to the known EMW R35/3 I see online.
I've attached a few more photos he sent me.

Do you see any red flags in the pics? Is this worth a few grand still? I'm not looking for a concourse bike, just something beautiful and fun. The /5 motor while not looking at home is probably a bit more reliable and easier to get parts for I'd assume.

I just sold a bike and was planning to buy a 2020 KTM 790 until I saw this and am now conflicted.

It looks like the bottom rail of the frame is tubular, not pressed steel, so that has been changed. Also, the R 35 frame was designed for a 14 hp single cylinder and a 750 is at least 3 times that. Also, the R 35 frame needed strengthening for a sidecar.

It might work but you might be letting yourself in for a lot of development work.

Charlie.

Update:
I purchased the rig and have been able to get more information on it.
The main frame, sidecar, controls, etc are CJ750, R71 clone. The front portion is an R35 frame that is welded around the R71 style frame. 1970 R60/5 motor. R12/R7 style fenders.
Bike was built by Jimbo's Classic Sidecar. I guess he is known for doing BMW motors into the CJ750s.

Overall I am happy. Has the pressed steel frame look that I love, runs good and was cheap. Maybe some day I'll be able to import an authentic one.