1980 MHR Frame No. 148

Hi
I’m looking to find out anything I can about Reg.no. RNK 422W,
I’m looking to purchase the bike and hoping someone on here can guide me in the direction of someone who may have records backing up the above.
Engine No. 089793

Sorry, we don’t keep records like that, we can arrange ref numbers for imported bikes but we do not have a frame register