Stupidly enough, OpenTransport 1.1.2 is only available as an update. This means you have to install OT 1.1.1 first, and then upgrade to 1.1.2, which is a bit of a bore. Having said that, OT 1.1.1 should work fine on its own and will probably suit your needs. You need to upgrade to 1.1.2 only in some special cases, for instance if you want to route a TCP/IP connection over Localtalk using MacIP.
OT 1.1.1 is contained in the following files:
OT_1.1.1-1of4.sea.bin
OT_1.1.1-2of4.sea.bin
OT_1.1.1-3of4.sea.bin
OT_1.1.1-4of4.sea.bin
OT 1.1.1 is contained in the following files:
OT_1.1.1-1of4.sea.bin
OT_1.1.1-2of4.sea.bin
OT_1.1.1-3of4.sea.bin
OT_1.1.1-4of4.sea.bin