Welcome to the forum , jkrjlr .
Perhaps , since you're requesting specific info about your cool little chairs , you could post another image of the tag/mod.# for us all to see (& be a bit more informed so as to help ya' ) , or just post the info ?
I wouldn't be hesitant to give them all a good cleaning (& a saddle-soap/murphy's oil soap cleaning of the leather - provided that it is not suede leather) & then decide about the condition they're really in & their appearance .
Also curious to see the bottom of the seat (is it sitting on a 'solid sheet' of steel , or is it screwed on through 4 metal 'tabs' on the chair frame ?) .
Without knowing a bit more , the era could vary , as these little guys were a somewhat popular (on & off) product/design for the Sears Company (& others) !
I'm of the opinion that having & keeping them in their original (even if it's sorta "as-is") condition is a plus , even if not antique (hold on to 'em long enough & they will be !) .
It is kinda common around these parts (PacificNW)to see these refinished , sometimes with powder-coating , & all fancied up for around $250.00 USD for 4 .