2 Cent George Washington Stamp Identification Help

Hello, I found this looking through some old stuff my grandpa left me after he passed away. I just googled stamps and recognized that this one (pictured below) was is his collection.

Now, I have no clue about stamps but tried to look it up myself but then I realized how many different versions of this stamp there is.

It measures roughly 2,5 cm vertically and 2 cm horizontal.

What I have collected so far is that it looks like there is 11 holes
per 2 cm vertically (maybe 11,5) on the stamp perforation and 11 holes horizontal.

I tried following this guide on how to specify which one it is and I would say it is Type 1 or 1A but I'm not so sure.

Thats why I went here for help.

Thank you in advance!

Welcome.
You are starting with a challenging stamp. You can download a temporary perf gauge here http://www.stampsmarter.com/learnin...rfGauge.html

Then move on to here
http://stampsmarter.com/1847usa/was...d32perf.html
and/or here
http://www.stampsmarter.com/feature...rank_ID.html

Don

Thank you Don.

It's still an enigma, however I measure I get it to a perforation of 11 or 12. And using the links you provided I have narrowed it down to either:

12 perf = Type 1 number 406
or
11 perf = Type 1/1a number 461, 499 or 500.

Is there some big value difference in all these versions and should I get it graded by a professional who can see it in person?

Nice light cancel on it too. It is a nice stamp.

What does that mean Imodius, but thank you I guess?