I have royally blundered my service design for this house with a mother-in-law apartment(I think?... in some fairness to myself, I am picking up where someone else left off). I have a remote 400 amp service on a well house 100 feet away from main house. I ran underground wires to house, and I went into an LB and then into a JBox which I used tap blocks to splice SER cable to the underground wire(without a disconnect-mistake #1)which feeds main house panel.Then from that panel I am feeding the mother-in-law apartment 100 amp sub-panel with main back feed breaker(mistake #2?) I realize now I need a 200 amp disco for SER cable that feeds house panel, and want to place it inside the house at closet point of entry, but that is a closet. Can I stick my disco in coat closet? And if I did would I get bit by 225.35 access for mother-in-law occupant? Which is my second question "Should I just get a rain tight disco and place outside meeting 225.32 and 225.35 in one fail swoop?"

This is my first experience in twenty years with this type of remote service and I am paying a hefty price!!

Thanks guys,
H20

I am wondering if the main breaker at twin meter(main service)qualifies as access to supply for occupants?

I personally wouldn't install it in a clothes closet anyway, but if the disconnect contains overcurrent protection, I would definitely say it's a no-go, at least per 240.24[D].
IMO, an outdoor disconnect located at grade level in a common area would meet the requirements of both 230.70[A],1, Readily Accessible Location and 230.72, Access to Occupants.

Thanks Kjay,
trying to stretch clothes to coat...
But ignitable covers both.