Hi,
you can get the handguns working quite easily, i've fixed just about every unit addon i've ever d/loaded for OFP and the process is not that hard, it takes about 5 minutes. about the hardest thing is to work out which model the unit uses.
here is the process.
1. copy and paste your RESISTANCE data3d.pbo file to your desktop.
2. de-pbo your copyed data3d.pbo
3. de-pbo the addon you want to fix.
4. go into the copyed data3d folder and copy the .p3d which corresponds to the addon. e.g. i fixed the STE Rangers addon and most of the units were just re-textures of the Resistance Officer (mc_vojakwo.p3d). paste the .p3d to the folder of the addon your trying to fix.
5.now u just have to texture it, open textureP3d, then open the newly copied .p3d.
6.it can help to also open the .p3d that came with the addon in a seperate window.
7. in the texture folder window of textureP3d type in the name of the addon folder. e.g. "STERangers\" no qoutes though. it's important to put the \ after the folder name or the textures won't work.
8.now just look at the already done .p3d and compare it to the new you will be making. just set the textures and then save the .p3d, you must call it exactly the same as the original (case sensitive) unless you feel confident enough to alter the config.cpp file. you must also save the .p3d anywhere but in the addon folder (textureP3D doesn't overwrite files very well they usually get f****d up.)
9.nearly done now, just delete the p3d from the addon folder and replace it with your new one.
10. use StuffPBO to pbo the addon and copy the new pbo into your OFP addon folder and start the game and enjoy your fixed units that WILL work with handguns.
all the tools i mentioned can be found on this site (or at least thats where i got them).
If you can't do it or you can't be bothered just send me an email on jaymzsob@aol.com and i can do it for you.