Welcome to the forum!
I moved that to the DaySailerII Only section of the forum, because the items discussed, holes from cuddy, doors, are a bit specific to the DSII hull / deck design.
For the door, look in the older posts for the DSII, there were some nice projects discussed that people did for those doors.
One guy split the door horizontally - the top 1/3rd could fold out for accessing some stuff during a trip, while the bottom 2/3rds stayed securely in place (until he took them off at night for camping). With that design, he could mount some nets for items like VHF, binoculars, etc. on the bottom 2/3rds as well as mount a compass.
Hull number: I'll let the DSII owners speak up - the DSII was built after the modern regulations for HINs were adopted, so hull number location should be standardized.
PS: btw, it's DaySailer (while the person sailing it is a day sailor

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