Then it must be an Elhoo with a Ford 997 engine, a Cooper type chassis and Renault gearbox and suspension components. From about 1962.
It is believed to have been built by the late Rauno Virtanen, and called the RV Special.
.....and you've solved it. I was going to point out that the Elhoo cars were F3 500cc cars from the early 50s, but a quick google search revealed that there are Elhoo FJ cars from the 60s mentioned on "a certain site". The rest of what you say is what I have as my notes on the car.
I'm going to call it an RV Special unless more information can be found. Well done.
PS I've just found out that this car competed at this year's Copenhagen GP Historic meeting, and the driver ran it as his Elhoo wasn't ready, so I think we can assume that it is a totally different car.