It's not likely that you will find a mystery that hews more closely to the classic format  for "Murder in a stately mansion with a domineering, tyrannical old person who controls the money". This is the variant in which the relevant group are made up entirely of family members or old "retainers". Most every author of classic mysteries has resorted to the device at least once, some have made it their favorite setting. In 1942 Heyers penned this version which certainly has one nasty Master as its dominant beastly one in addition to the usual quaint, weak, theatrical, determined, overawed, frightened, frustrated dependents. Heyer draws the characters well, although the number of them make the less relevant somewhat difficult to separate from each other. The story moves along at a leisurely pace, giving the reader a chance to sort out the players and get a feel for their traits. We know who dun it before the crime is committed, or.........that you will have to find out for yourself.