Incidentally, I don't know how I missed this for all this time, but here is a link to the AE website's shoe care guide:
Also, Chris, it lists your Holbrooks as brown chromexcel leather and recommends AE's Leather Lotion.
My Barton model is not listed by the way (many vintage models are excluded, it appears to me).
My Holbrooks were purchased in 1998 and are model 1568 in chocolate chamois. 1558 is the chromexcel