Rs113A Proprietary Revenue Stamp

Hey folks, I'm new to the forum...quick story: I used to collect when I was a kid with my dad who was a pretty avid collector. Sadly, he passed away recently and I've inherited his collection and have been going through it. Enjoying getting back into collecting immensely!

I know a bit about stamps from him teaching me over the years, so I'm fairly certain I have identified this stamp properly but from what I'm seeing, this seems to be an extremely rare stamp, an RS113a. I'm seeing information online that there are only 20 known copies, and if that's true, I think I may have copy #21. But I also know enough about this stuff that if you think you have a rare stamp, you probably don't. But this sure looks like what I think it is...

If anyone is familiar with proprietary revenue stamps, I'd be interested to get additional opinions on this one. Thanks!

RS 116A?

Ahh...yes could be an RS116a as well. 116a looks more red to me than mine but it could well be that mine just had a hard life and the color is a bit faded. What exactly is the difference between the two? Paper type? Color? Something else? Hard to find much info online about these stamps...thanks.

Rs113a is shown as Bister.

https://bid.siegelauctions.com/powe...SortOrder=-1

Got it...yea I see that now. I have a bit of color blindness, not a great trait for this hobby, so the difference for me is subtle but I do see that 113a is more brown and 116a is more of a red. And my copy looks to lean more in the red direction even if it is a somewhat faded red (at least to my lousy eyes!). Thanks!

This is not the bister, it's the red. If it is the old paper it is still a very scarce and under cataloged stamp. It could use a bath in warm water.

RS114,115,and 116 on old paper are all very scarce and under cataloged.

A bath is a good idea. When thoroughly dry, watermark test it. They can be a bit hard to see if the paper is thick.

How would you all recommend I clean it up? Just in some warm water in my watermark tray? Is there a special cleaner that's recommended?

Yes, and easy to find!