Different Perforations That Aren't Mentioned In Catalogs.

Rob Roy, maybe I can help with the Bulgarian stamps.

In the late 1990s, Bulgaria issued a few definitive-sized series. The one you posted is from a six-stamp series depicting churches, and yours is Scott 4155. Other examples of these short definitive-sized series are Scott 4101-4106 (fountains) and 4114-4118 (gold artifacts). Most of them were reissued in 2003 with syncopated perforations, which in Scott are listed as letter-varieties (4101a-4106a, etc.). They're listed directly under the original issues in 1999 and 2000, not in 2003.

I don't have any of the syncopated-perforation varieties from the churches series, but I have a couple of examples from the other series, and they retain the original issue dates - 1999 instead of 2003 - in the lower corner. If the Bulgarians kept up the same policy as they did with the others, you have Scott 4155a/Michel 4480CS.

Michel also combines the original issue with the syncopated issue. The churches series is chronologically "2000, 1. Sept.", though in the listings below the illustrations Michel states "1. September 1999", which I think is a typographical error. Scott gives "2000, Sept. 1" as the date of issue, so I think that is correct. However, Michel gives the date for the syncopated perf. reissues as "18. November 2002" and Scott says "March 2003".

Michel and Scott don't always agree on dates of issue for Bulgarian stamps. When there are differences, they are usually a few weeks apart. Four months seems like a lot, but I've seen that much of a difference on a few commemoratives and topicals in the 1980s and early 1990s.

Thank you for the information. It is indeed confusing to see an issued stamp marked with an older date of issuing.

As for stampworld, I do try to use it before coming here, and for this post, I couldn't get an answer from there.