Vintage Seamaster Quartz Dilemma

Hello fellow Omega fans,

I find myself in a bit of a dilemma and could use some advice.

A month ago, I bought a vintage Omega Seamaster Quartz (Ref. 196.0073, Cal. 1315) and took it to my watchmaker for a full service.

Mechanically, all the parts were clean. However, after the service, the watchmaker noticed a daily loss of about 20 seconds.

Shortly after, I managed to pick up the exact same model for a very low price as a gift for my father, it was a lucky "attic find." Surprisingly, this second watch only loses about 1 second per day, which is significantly better than mine.

Now, my father feels the watch is too small for him, which leaves me with both. I need to decide which one to sell and which one to keep:

• Watch 1: Freshly serviced, but losing 20 seconds a day.

• Watch 2: Unserviced (attic find), but running beautifully at -1 second a day.

Absolute accuracy isn't my main priority, but I am worried that the 20 second delay on the serviced watch might indicate a failing electronic circuit or block.

What do you guys think? Which one should I keep?

I'd keep the -1 sec one and give the other one back to your watchmaker to sort it out? Was it loosing time before the service already?

He thinks so cause he says It is related to the magnetic drive.