Hello Trev,
Yes it is Tillander and there is no doubt about that. Here are some more marks used by Tillander.

Koruteollisuus Tillander Oy Helsinki 1946-1976. This mark is usually on older spoons like this.

Kunniamerkkitehdas 1941-1945 (Medal factory owned by Tillander)

Ato-Koru Oy (owned by Tillander) 1960-1971

Oy Alexander Tillander Ab 1993-
The next marks are ordinary "letter marks":
AT. or A.TILLANDER for Alexander Tillander 1921-
AT or A.T. for Tillander A. Ab Oy 1980-82
ATILLANDER or A. TILLANDER for Alexander Tillander Ab Oy 2008-
VL for Tillander/Lindman 1918-1921
The last one is the oldest and the mark for the new start in Finland in cooperation with Viktor Lindman.