Here is an excellent resource for those who want to study the early stamps of Persia/Iran; and gain knowledge as to the forgeries and reprints.
www.persi.com
I have the 2002 catalogue for work on 10-12 pages of old Persian stamps that came with a world wide collection I bought in the 1990s. Maybe I'll get to them and maybe not, since Persia/Iran is not a specialty area for me. Later catalogues are expensive, but, I would think, essential for study of these old Persian issues.
The Serrane Guide, published by the APS, has some references. One can further check out Linn's Focus on Forgeries, by the late stamp forgeries expert, Varro E. Tyler. Professor Tyler also did a forward for the Serrane book. I suspect, but have not checked, that the APRL will have some other sources, available for check-out by members.
Anyone in US not familiar with the APS/APRL, I strongly advise becoming a member. Visit:
www.stamps.org for more info.