Heads (toilet) door closing mechanism

My heads door closing mechanism, after 50 years, has a lot of play, so when I turn the wooden knob to open or close the door the plunger which goes into the plate in the door frame does not release.    So sometimes it is very difficult to go into or out of the heads compartment (both situations can be embarassing).    The fault is in the latch assembly (photo attached).   The spindle joining the two door knobs goes through a square hole which is no longer square.      I am looking for a replacement latch assembly or an alternative idea which does not require major surgery on the beautiful door

Dear Richard,

is it a Kwikset (please see attachment)?

matteo (47/069 Vanessa)

It does not look like a Kwikset but looks like the (probably) original cylinder lock, see attached pic.
Years ago I tried to find a replacement on a boat show but was repeatedly laughed at; original quote: "this kind of quality manufacturing died in the 80s". So if Nautor does not have them anymore, you can probably go with two strategies.  My preference would be to look for a metal shop that can repair the square receptacle, or at least stabilize it so it cannot bend any worse, and adapt the square spindle so it can be inserted without the play, e.g. by welding small pieces corresponding to the receptacle deformation (it may not be square anymore, but it is out of sight anyway). Alternactively, you could check if the Kwikset fits with the measures of your door -- even the beautiful cylinder locks can only live for so long.

Martin (Vellamo, 48/039)

Cylinder lock

Dear Richard and Martin,

the good news is Kwikset are still available (they even have a shop on Amazon!), so, unfortunately for the silly man who told Martin his "pearl of wisdom", you can buy it online (if it's a Kwikset).

All best,

matteo (47/069 Vanessa)

Dear Matteo,

I agree that it looks very, very similar and is most probably at least alike (so regarding the guy on the boat show, may his name be forgotten!). Can you match the diameter you have on the boat to a part number on the Kwikset website? There seem to be no data available.

Martin

Dear Martin,

I am now in Maastricht "on holiday" (not really but from time to time I have to deal with my job too!) and back onboard on 24th, will check and hopefully will post a part # !

All best!

matteo (47/069 Vanessa)

In the meantime many thanks to both, we have already made some progress