Not a Tikka....
It does have a very similar mark (to FN) on the bolt handle but once I cleaned the years of dried oil off the metal, it is not an FN mark.
The "Forest" name led first the auction house and then myself astray. Wasted many searches including the word "Tikka" which turned up the few examples I mentioned. Probably people who made the same mistake.
It is a "hardware store gun" made for Waffen Frankonia of Wurzburg, Germany. (Similar to JC Higgins Model 50)
Rifle was roofed in Munich in April of 1966
Can't prove this, but based on the font/style of the serial number I suspect the action and barrel were made by Heym.
Spent a few minutes here and there over the last few days looking up pages and using Google translate and found similar examples.