Strike 1- The barrel profile tells me that barrel was replaced with an aftermarket barrel. Doesn't have an FN barrel, not an FN. Period.
Strike 2- The stock is an aftermarket stock. It may be attractive, it may be functional, but it is not an FN stock, so the rifle is not an FN.
Strike 3- Yes, Browning imported FN rifles under their name, but those rifles had some very distinctive features and were marked as Brownings, and yours is not a Browning.
Rifles with FN actions were also sold by Montgomery Wards, Sears & Roebuck, and JC Penneys, as well as private-labeled for H&R, Parker-Hale, and High Standard, and most donor rifles were of these last types. FN also imported and sold bare actions for gunsmiths to build rifles on.
If the gunsmith did not think enough of his work to mark it with his name, it is just an anonymous gunsmith, good or bad.
The "extra-wide trigger" is not something special, it is an Ace trigger shoe, sold at many sporting goods stores for under $5 at that time.
If you are interested in selling it, PM me.