I have a really nice Ro Go and Gav is right, the red is faded on this example. Artwork is really good, but there is not that much to do on the playfield except collect bonus !
I like the Nordic / Viking theme, and I prefer the Ballys to the Gottliebs and Williams of this era. I would check that the game has chimes (its from Europe). It is defintely a rare machine, but not as rare and collectible as other Bally titles of the era (Fireball, Old Chicago, Capersville).