Wheel milk, does it have a shelf life?
I've never used it before but have had some in the shed for about 18 months,
I've just opened it to use and it seems a bit thicker than expected, Stans is quite runny when "fresh" but this has the consistency of thick custard.

Mine is definitely not like custard. Unless it has dried somewhat it should be about the same consistency as Stans.

Is it still full?

Yep, i never opened it till today, i've just squeezed it a bit and the thick stuff came out the end 😯 its a lot runnier underneath, cheers.

give it a shake