Fluid trainer, repair leak?

I have a Travel Trac (Performance Bicycle) Century V fluid trainer, vintage c. 2005, that I’ve pressed into heavy-duty service during the pandemic.

It’s been working well these past months, but seems to have developed a leak recently.

Is it reasonable to try to repair the leak? I found a video where a guy fixed his JetBlack fluid trainer by just replacing an O-ring.

Rather than trying to fix it myself, I’d like to hand off the task to a professional. Is there a shop in the US (even better, the Bay Area) that’s experienced with this repair?

I’d hate to trash the otherwise-fine trainer for a failed $1 part.