Gibba Gobba,
As a common user of the Source SDK's Hammer tools, I can assure you that with the correctly placed .mdl decompiler by Cannonfodder, you can decompile any Source model file. (You can use GCFScape to extract the content from Half-Life 2)
If all fails, there is a .mdl compiling suite with FragMotion, which has a 30 day free trial. So I suggest using that.
Once you've got the .smd files, you'll need to merge them in to one animation file (3DS Max is the best option for this, although quite hard on the average pocket), reposition the model, and export as .x using Pandasoft's exporter.
The you just need to set up the gunspec.txt to fit your crowbar.
Personally, It seems like more effort than it's worth for a home project, dontcha think?
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