I like Viking ISS but I would prefer to have the same tobacco without the menthol.

Which Viking plain blend is the base for the ISS e.g. Dark, Brown, Scotch or Thors Hammer?

Judging by the colour, moisture and nicotine content - Brown. Have a look here: The Viking Snuff Other English from £3.60 - Wilsons & Co

As a big Viking range fan myself (in fact, I just recently ordered two 100g tubs of Dark and Brown for the coming autumn), even in the format as now made by WoS, just as volunge mentioned, the Viking Brown is what you want here. Seems to me that it is the same base flour as the ISS.

I love the Viking range, Thor’s Hammer is my favorite.

Thanks for the responses.
I am excited about getting the plain version. ISS itself is very tobacco forward so once i get some plain I won’t need to snuff that messy Taxi Red anymore to get straight forward tobacco!

It’s Viking Brown for sure. Nothing else.