Do Scott #s Change Over Time?

I am going through an accumulation stamps acquired in my youth and am perplexed by one item that is probably the most expensive item I ever bought.

In 1969 I purchased a stamp from Juliard Classics, a dealer with an impeccable reputation who was ceasing operation. The stamp was New Zealand # 7 described as "1855 2p. blue on bluish Extra Fine".

I went to the library yesterday to look at what Scott shows currently, and #7 is described as 1p. orange issued in 1858. Based on looking at the reverse side, the stamp I have appears to be printed on light blue paper so my best guess is that it is New Zealand #5. I am wondering if what is now #5 was once #7. (I note that lot 168 listed as Scott #10 appears to be current Scott #8

Any ideas how I could pin down what I actually have would be appreciated.


*** Moved by Staff to a more appropriate forum. ***

Scott does renumber stamps at times and if you look at the front of most catalogue they list the changes in that edition.

Thanks Angore. Who knows what year such a change occurred. But thinking about that inspired me to do a search for "scott stamp catalog archive", and lo and behold I came across a copy of the 1940 Scott catalog. Sure enough, what are now Scott #s 5 and 7 were numbers 7 and 10. The reason being that for whatever reason there were no numbers 2 and 3 in 1940. So now I can justify identifying my stamp as #5.

Just a side note, in my 1940 Scott catalog, US #1 is listed as US #28. Scott #1 was a postmaster provisional, I think (I don't have my catalog at hand).