I picked up a 1970's SS Sekine roadbike for next to nothing in December. It was converted from a 10 speed to SS by the previous owner. Although it's a great ride, I'd much rather have it fixed (Been using my friend's FG more often than my own bike.) My question is, will this bike be worth upgrading or is it much more cost-efficient to buy a used fixed gear? I don't have too much technical knowledge on bikes, so I don't know what needs to be done to achieve FG.

Frame: Steel
Wheels: 27x1-1/4 alloy
brakes: centre-pull cantilever
Cranks: cottered, 52t
Dropouts: Semi-horizontal
BB: 68mm 1.37"x24TPI

If I didn't provide enough information, let me know. Thanks!