having worked on more than a few of these systems and found a few issues constantly popping up, In New Zealand
we receive cruisers after a diagonal crossing (usually from west coast
USA or panama) of the pacific, couldnt get a harsher case of constant use if you tried. The danfoss compressors are a bloody sturdy wee beast to say the least, problems arise mostly from installation
or air ingress to internals, air contains moisture which in turn clogs capillary tubes, creates acids and sludge etc etc . The capillary tube used is really quite tiny and takes bugger all to block therefore the total absence of air and other contaminants is critical. Have found on more than one instance where the system contained considerable noncondensables, whether this was a result of a factory/ manufacturers issue or due to instalation etc is not always clear, one thing that is clear though is that the connectors will in time leak, and in all reality most when installed never come out unless it's for troubleshooting/ maintenance
issues, have also found the seal when disconnected can and will leak so why bother having them there !!
Another issue that Richard mentioned a while back is with regards to fans and electrics, even though your unit is " keel cooled" the compressor still requires a small fan to flow cooling air over the electrics and remove some compressor mechanical heat I would advise to fit one as it does make a helluva difference.
Thermostats can be roughly fine tuned for hysteresis (diff between switch off and switch on) by partially insulating the thermostat capillary with thin plastic tube leaving the evaporator end of it exposed where it contacts
My recomendation would be to
1/ remove refrigerant charge and weld out ALL connectors and change the drier
2/ Vacuum the system for 12hrs(overnight) minimum
3/ Make sure there is a fan at the compressor (cools electrics and does to a degree remove mechanical compressor heat
4/ add recomended charge of 134A ( have found everything from R12 to R404a and in one instance R22 in these systems)
5/ cover thermostat capillary with thin plastic tube completely except where it contacts the evaporator
6/ discard original access port cap and replace with 1/4" flarenut and flare bonnet ( make sure that "whoever" checks the access valve doesn't leak after gauge removal)
That should give you a totally sealed system with few if any weakpoints...............enjoy