1- What sort of staff would be on hand?
2- What would happen if a non-member walked into the place?
3- Could a non-member simply walk through the door or would there be doormen outside of the place ensuring that this didn't happen?
4- How would a club member receive his mail - would he sign for it or would a servant accept it for him?
5- Who was actually in charge of running the place? I'm assuming that there would be a steward or concierge or maitre' d' overseeing the place on a day to day basis.
The search terms I used lead me mostly to the sort of thing I found on Wikipedia or job postings at clubs or info on strip clubs. I've got a copy of What Jane Austen Ate and Charles DIckens Knew but it doesn't mention anything at all about clubs.
Search terms - 19th century gentlemen's clubs, gentlemen's club operations, private club operations, private club staff