Hi I have a Denfeld Police seat fits most R models but not the R80G/S with the rear rack (it is a tad longer).
The seat is an original BMW police stock.
Top upholstery is fine and pliable, the rear vertical panel can be either repaired or changed. The front vertical panel can be either gaffer-taped or changed. Seat pan has surface rust otherwise solid. Foam is pliable and comfy. It has the original glovebox also the orig hardware which is expensive to buy if you do not have it.
I have seen these selling on ebay for $400 buy it now when in top nick and $200 when in ok condition. Lets say $150 for this. I am in Germany right now. Postage to the US will be around $50.
Please PM if interested. I am giving this a try then it will end up on ebay if no takers. The seat owes me $150 unfortunately. That is what I paid for it :(
Inerested parties please contact me.