My refrigerator still uses R-12. What are my options?

[Joe500]

I have a Frigoboat AV-12 refrigeration system in my sailboat. I think it is the original refrigeration from the 1980s. I have owned the boat for fifteen years and have not done anything to maintain the refrigeration. The refrigeration still works; in the fall, it is enough to keep food cool, but in the summer, I have to supplement it with ice. I leave it on the max setting, it runs 24 hours a day consuming around 5 to 6 amps. Frost builds up on the evaporator and if I put something inside the evaporator it can even freeze it.

As you can see in the photos, it looks like it uses 0.125 kg of R-12. I understand that R-12 is no longer produced, but can be purchased on the secondary market by licensed technicians. The following options occur to me:

1)Find someone with R-12 who'll inject a little into my system. Based on the photos, does my system have an easy port for topping off the refrigerant? My boat is in Barnegat Bay now in New Jersey. Anyone know a person nearby?

2)Find someone to remove the R-12 (I imagine you need a license and special equipment). Fill with alternate refrigerant. Looking over old threads from 10 years ago, it seems there's some debate as to whether this will work and what other parts, seals, oil need to also be replaced.

3)Throw out the entire system and buy new. Can I remove the whole system myself without spilling refrigerant or do I need to hire someone? I imagine I can install a new system myself since it comes with refrigerant inside of it. Do I need to replace the evaporator in the icebox? I'm not sure how it is attached or how easy it is to access it. Everything else is really easy to access, as its under the kitchen sink. Any advice on brands or models? My icebox is about 3.4 cubic feet in volume.

Thanks in advance for any advice.
Joe