Scott # 948 - Centenary International Philatelic Exhibition

Hi guys...Just picked up a few things at an auction a couple of days ago..One was the ""Centenary International Philatelic Exhibition"" sheet which I believe is Scott # 948.

There were 2 other stamps, but cant find a Scott # for them..They look like reprints of Scott # 2 and #3..Now, I was reading originals VS reprints..I cant understand how to tell the difference..Can my American friends set me straight..Thanks.

These are #948a & 948b.

Thanks kevin504...Didn't know it was that easy..Appreciate the quick responce.
Robert

In case anybody didn't know, 948a and 948b are stamps somebody has cut from a 948 sheet to use separately. Not so great for collecting, but perfectly valid as postage.

The sheet has reproductions (sort of) of the first two stamps the US issued. The colors are totally different. Plus the small initials on the sheet read B E & P, Not the original R W H and E.
You may be confusing the originals (Scott 1 and 2) with the reprints (3 and 4) made for the centennial exhibition in 1876.

The differences between 1 and 2, and 3 and 4, while subtle are easily detected.