I've heard the BMS ambulance on 464.7750R/D743, which is licensed to their Lawrence facility near 206 & Provinceline; fire may or may not use the same. I have 464.975R listed as Fire Ops, same campus, but I'm not sure how I came to this conclusion and I know I haven't confirmed it. One other repeater there (464.475, Security?) has been confirmed to use D743, so it's possible they all do.
Mercer County central's web site used to list 468.9625 for the BMS fire brigade, which is licensed to BMS at their Hopewell campus (old Mobil facility) for mobiles only with mobiles, no repeater, also licensed on 463.9625. I haven't confirmed this either, and plenty of other stuff on that now-deleted page was outdated.
The only channel I show for BMS in Hamilton is 451.6250R, no idea on usage or PL/DPL.
For listings of all BMS-licensed channels in Mercer County check out the business listings for each town on my page at http://www.jim-robbins.com/radio/mercer.html; there are a handful of repeaters and dozens of low-power mobiles-only channels.