Honda-SOHC

Greetings.
  I’ve just discovered this site and saying hello.
My first bike after borrowing a friends 250 super dream to take my test was a maroon 400/4 in 1980.  Managed to get more than I paid for it in PX when I mistakenly traded it in for a xj650 yam.
  My second one (same colour) I bought in the late 80’s. It took myself and girl friend to the 1990 TT.   
  Today, whilst clearing out some old draws I found a receipt belonging to my late father.  It was for the purchase of a new Honda 400/4, in red, dated August 1st 1975. He bought it from his good friend and Honda dealer, Alan Mountain (Mountain’s motorcycles) here in York.  Price, £660.
  I remember the bike well, riding pillion with him all over.  I was aged 12 at the time. Great memories.
  The reg no. was MVY 673P.  Long shot I know, but does anyone on the forum know of it’s ware abouts?  Seems it was last taxed in 1982, so I doubt it has survived, but any info would be greatly appreciated.
  Sam.