Viking records (Nu-Phonic Corp.) was a short lived label from New York. It was only active in 1941.
Viking records are neither vinyl nor shellac. The center layer appears to be 1/16" thick chipboard or other semi-sturdy material, sandwiched between two flexi discs similar to Hit Of The Week records. All three layers glued together with labels glued on each side. Prone to labels falling off and/or missing entirely and extreme de-lamination of the three layers, to say nothing of the rippling often seen in the playing surfaces.
Source: Discogs