OK, Zelman is going to jot down the foreign materials he found in the blood sample, and wrack his brain a bit for some folkloric, medical, or legendary/mythical herbalistic properties or tales about the things he found; I know you tested against Chemistry and Pharmacy, but he has Medicine 65, Natural History 25, and Occult 30, and Know 100. Failing anything coming of that, he's going to head to the library attached to the lab to try and find something about them or about herbalism as used in such weird things. He has Library Use 50.
Robert, if he's exhausted the upstairs library, will excuse himself and head down to check on Zelman. He'll try to add his two cents to what Zelman has found, having: Anthropology 51 (in case the combination of ingredients lends itself to a particular group,) Chemistry 16, Natural History 19, Occult 15, and Know 85. Failing that, he'll join Zelman in the downstairs library, helping Zelman's search and continuing his own research into the tattoos and anything related to the Southeastern Pacific materials May's father collected. Library Use 45, Antrhopology 51, Archaeology 61, History 45.
O'Neill will skulk along to the basement, having been given an excuse by Charles to investigate down there. Assuming he can pick up a lamp, lantern, or torch, he'll investigate the junction of the old dumbwaiter and the odd (for the basement of a mansion) system of tracks. He has Track 10, Spot Hidden 50, Sneak 50, Locksmith 36 (if it comes up,) Listen 25, Hide 29, and Climb 50 (if it comes up.)
If I can figure out a way to work into the post a way for Zelman to communicate with Charles, I'll have the detective try to scare up a relationship between the May family and any group or individual specializing in herbalism or such odd corpse-tampering; also, he'd probably think it useful to try and look for any ties between the Mays and any shipbuilding or carpentry involving pine tar. He has Know 70, Law 45 (to interpret any possible real, tort, or liquid connections,) Library Use 25 (to check through the Mays' papers and notes,) and Spot Hidden 60.
I can't stand nothing dull
I got the high gloss luster
I'll massacre your ass as fast
as Bull offed Custer