Russ Folsom adds this note on the German
The German 163.Infanterie-Division, also known at the time as the 'Engelbrecht Division' (after CO Gen.d.Artillerie Erwin Engelbrecht), was allowed to cross neutral Sweden from Norway to Finland to became part of Mannerheim's Finnish Karelian Corps (in reserve) by 30 June, 1941. I've read that this particular group of German soldiers passed through Sweden without arms or armament of any sort, carrying only personal belongings in normal passenger cars with the curtains drawn on the compartments to remain anonymous [This same division had played a major role during Operation 'Weseruebung' (the invasion of Norway in 1940), and would fight for the most part in the northern salient of the Russian front, shattered by Spring 1945, and disbanded to be used as cadre for the ad-hoc Kriegsmarine 3.Marine Infanterie Division.]
As far as I know, this was a one time Swedish allowance of such a large (divisional) contingent of German troops to cross from Norway to the Eastern front. Subsequent crossings were allowed of 'neutral' Swedish territory, but would thereafter be made by German soldiers travelling singly or in small groups as replacements to units in the East. It is estimated that nearly 250,000 Germans passed from west to east in this manner.