The conclusion of the Spanish Mauser dept. in my collection has come home this week and met
an as-new bayo w/ sheath which was purchased some weeks ago in anticipation of the FR-8.
La Coruna 1956 with a non-matching bolt, therefore it didn't break the bank.
FWIW, there used to be a bayonet for the FR7/8 in a box on the floor at Hansen's Guns (Southport, CT). You'd have to call about it, since I haven't been down there in awhile. Never quite saw the point in getting it for my FR-7... http://hansenguns.com/
If you want a navigator to get you there, let me know (assuming you are coming down I-95 or I-395).