Of the 3 vertical sinclair porcelain signs, which one is the rarest?
1. Opaline
2. Mobiline
3. Pennsylvania

I would say mobiline...

Did you pick one? I'm looking for some.

mobaline .... absolutely no doubt....
was not in existance very long before lawsuit was filed by 'Mobil' and they were forced to quit using 'Mobaline'...I believe it was only 3 years.....
Pennsylvania and Opaline continued on.
there are two different kind of verticals
1. self framed
2. just flat with holes/w rivots to hang
been told the self framed have not been repoped where the others have....

Mobilines are the rarest. Especially in 7+ form. They were told to destroy em. They were made only in 1932

I agree with the above statements
followed by the Pennsylvania..

Yes, notchcad I found a Mobiline but have not picked it yet. It is very rough rated maybe a 5-5.5

is it not 'mobaline' or is it 'mobiline'?

This one is not self framed, it is the flat version

They never made a self framed mobiline. Only flat. Even 5-5.5 I'd be interested in if you can get it. I need one for my fence next to the other two rough ones I have. And it's mobiline. Not mobaline. If it was mobaline why would Mobil care? Lol

Signs have Grommets, not Rivots [Rivets]!

Here is mine. Not the greatest condition but it is mine. No it is not for sale.

I have the Pennsylvania Flat Version. I framed it though. I get to see it when I'm at my sister's house since it's on her shed LOL!

FYI
The Pennsylvania and Opaline are both in the flat and cookie cutter versions. The Opaline also has one version with "Oil" on the bottom and one with "Oils". I only ever saw the "Oils" on a flat version. I saw a repo Opaline sign on eBay this week that looked pretty good. It was painted not porcelain as far as I know. Another one to watch out for...