I recently inherented a collection of loose stamps from around the world. I have spent the last week carfully looking through them. Most date from 1900-1960s; most are canceled. I have been tring to learn more about my new collection. This hobby is very confusing to a novious. It seems like most of my stamps are worth a lot more in sentimental than actual value. On of the two cent Washingtons I found is stamped in red ink on the back as "perf 10." I found some information online, but I'm not sure what I have if anything. I'm not even sure which edge I should be counting along... top? bottom? Any help would be greatly appreciated. Thanks!

