Not many jewels.
Not cased very tight.
Any part in the train not jewelled is subject to arresting wear.
Old enough to have loose or dislodged impulse or pallet jewels, worn pallet arbor and or holes, center wheel pivot and hole wear - hell it's crude enough to have mainspring arbor hole wear.
Tweaked guard pins, skinny escape wheel pivots, rusted hairspings, bent and or misadjusted banking pins.
I've seen all of the above and more on this exact series including cracked and worn jewels.
The higher jeweled versions can often be serviced and brought to a reasonable level of performance without supernatural efforts.
That said, an actual watchmaker can rapidly diagnose any of the aforementioned issues and most others. Many servicers experienced only in post war watches are ill prepared to polish or replace pivots, bush or up jewel holes or tighten up an escapement rendering them unable to do other than replace parts - if available.