This tool allows you to convert Source V28-37 models seen in 2003 leaked build of Half-Life 2 to V48 used by Source 2007 and 2013 branches.
The usage instruction is in the readme file of the archive.
Download
Nicknine's MDL converter doesn't seem to work
Here's what I'm typing (<MODFOLDER> is "E:\Steam\steamapps\sourcemods\half-life2-003"):
Anybody know why this happens?