There are, or at least were in the relatively recent past, immense stockpiles of surplus JAN tubes. I.e., they could well be legit. The label looks a little messier than I'd expect on a legitimate JAN tube, too -- but there were tubes being made - somewhere - for US military purposes (?!) into the '80s, at least, and I really don't know what the quality of the last of them might've been like.
I reckon they're running in a plate-starved "space charge" configuration -- but, who knows?! They're probably doing
something, but not necessarily anything good with respect to the input signal(s).
EDIT: PS, persuant to
@fpitas's post, they could be connected as triodes.

I don't intend this as a value judg(e)ment, just a statement.