Well I would suggest extracting them from HL Source vpks, then using Crowbar Tool. It lets you decompile a model, and then recompile it using Valve's tool called studiomdl. It's included in the leak (in anon-hl2\bin folder) and it is necessary to use that particular version to compile models for the leak. You can set up Crowbar to point to the leak's studiomdl. WIth things like props, it shouldn't require much, or any, editing to recompile them.
Crowbar can be found here
http://steamcommunity.com/groups/CrowbarToolIt can unpack VPK archives, it can decompile unpacked models, and then you could recompile them, provided you point it to the leak's stuiomdl.exe (under Compile->Set up games->Model compiler).
Also I don't think HL1 has a soda machine model, I think it's always built with brushes.