Repair Frigoboat tubing leak

[nhcruise]

I have a late 90's Frigomatic AV12 refrigerator compressor with what appears to be a pinhole leak in one or both refrigeration lines. I've added gas a couple times, but it doesn't seem to last long. I was hoping the issue was with the O-rings but replacing them didn't solve the problem.

There is a lot of corrosion where the fittings used by the Frigoboat quick-connects are brazed onto the copper pipe. A leak detector indicates gas around the area of that corroded connection. Is there an easy fix? I was wondering if I could replace the quick-connect fittings with 1/4" and 1/8" compression union fittings. Since I don't plan to disconnect it in the future getting rid of that problematic fitting could eliminate future leaks.

If I cut out the quick-connect fittings, what's the procedure to evacuate the air before recharging? I can borrow a vacuum pump from a friend. Do I need to connect to both service ports or can I just vacuum from the port I've been adding refrigerant?