This is quite a simple job, even for a conversion. All i done was extract the model & sounds out of Half Life's GCF files, rename model & sounds, and convert sounds to new frequency. I done this cause i remember once upon a time Fuzzy releasing conversion of the HL sentry, but i never found a working link. Since it was such a simple job i done it myself.
All credits go to Valve Software.http://www10.brinkster.com/villem/HalfLifeSentryTurret.zip
(please, open in a new window, if the download fails try again, Brinkster is a bit picky about hotlinking).