Norwegian 830 Silver Tea Caddy Spoon - maker?

[Adam.NYC]

I believe this is Norwegian silver. It is marked with the initials F and I, intertwined and a butterfly. Couldn't find this mark on the site. Does anyone know who this is? Also, it is about 4 inches long. I assume it is a tea caddy spoon? Thanks all.

[Tosten]

Your spoon is made by Julius Marinus Frisenberg on Lillehammer. b. 1844, d. 1900, in work from 1868.

[Adam.NYC]

Thank you!