Recently came across with this Longines. Looked good to my untrained eye. The only marking on the watch is on the back "10k gold fill". I am able to remove the crystal but couldn't remove the crown to check the caliber. Anyone have any information ?

Thank you.

 

High probability its a caliber 370, mid 1960s.

 

Thank you very much. Didnt' want to take it to watch maker since the watch is NOS and never been out of the box

 

I like the linen dial, nice catch.