Is #63506 a provious release?

[BlueFox]

Is item #63506 (Conrail GP-40 road #3088) a previous release of this loco?  In my 2011 Catalog I can only find #63505 (page 53, Conrail GP-40 road #3072.)  I believe both these locos are only DC versions as far as I can tell.

Frank