Fix title… there was only one volume of Legion X-2 (Legion X II on the cover)
There were 2 volumes of Legion X-1 (Legion X I on the cover). So the series in core as Legion X-2, Vol. 2, should either have the Vol. 2 removed, or changed to Vol. 1.
On missing issues, you currently have only #1 and #7 in Core, here are the other missing issues:
#2 May 1990
#3 July 1990
#4 Sept 1990
#5 Oct 1990
#6 Dec 1990
#8 May 1991