Hi George, welcome to the Rug Rag Forum!
This is an interesting question. Please do attach photographs when possible.
I actually have seen several Persian rugs with crosses in them. This would include some older Kermans with European influenced motif. Usually this was in conjunction with some sort of depiction of a figure head. Several months ago I came across a low grade Tabriz Rug in an associates inventory which had several crosses in it. No pictorial depiction, simply a panel design with crosses substituted in several panels. So, to answer your question, they do exist. More commonly, there are Moroccan rugs, or possibly an Indian interpretation of such which sometimes had crosses woven in them as well.
As for the signature, this is a post that
should help clarify some of these things:
http://www.rugrag.com/post/Authentic--Signed.aspxThanks for bringing this to the forum. Looking forward to the photographs!
Sincerely,
Dave