I think Richard Sachs was correct in his assessment of this frame, by saying that it is a Speedwell.
I recall some publicity about the machine in England some years ago, but like so many of these publicity stunts the project was short lived. I have a couple of Speedwells and recognise the Lamborghini as a Mark II version due to its slightly bulbous seat-stay top-eyes, and fork crown. The crown also featured on the the Mark I version, but the top-eyes were long and very chamfered. The frames tended to feel quite flexible when ridden hard, and perhaps the beefed up seat-stays were an attempt to add some rigidity. To try to keep a customer happy when I was a little behind in building his new racing frame I lent him a 22" Speedwell Mk I to race on. He brought it back after a couple of races complaining that "...it's like riding a bag of rubber bands!"
As I recall the Mark I version was the one used by Louis Ocana. in the mountain stages of the 1973 Tour de France.
Norris Lockley...Settle Uk