Thanks for the responses, I'm having some fun with the scans and some of my other cards. I have a couple grand slams with this group (four variations of same pose)
For the Detroit OJ collector, the only way to hit a grand slam on poses would be to obtain the only two possibilities from 1887, N172 & N175, together with the only two possibilities from 1888, N172 & N173. While the 1887 N172 is easy (relatively speaking), the other three can be very difficult.