Yes it is. This is all achievable thanks to RPearson's work.
The files can be found in Todd's RGS-20, change k27_loco.gs to a text file.
*The generic custom script files to add to his older UTC version loco's directory are:
*steamlococabindata.gs
*SteamLocomotive0905.gs
*In the loco's config add this - note location in the file isn't critical but can't be within extent of another container:
*script "SteamLocomotive0905"
*class "SteamLocomotive"
*The special custom rgs20 script files to add to the newer loco's directory (with loading sand capability) are:
*steamlococabindata.gs
*rgs20_loco.gs
*In the loco's config replace the existing class and script tags with this:
*script "rgs20_loco"
*class "RGS20_Loco"
*The script files to use to add to any of the cab interior's directories are the generic scripts:
*steamlococabindata.gs
*steamcabinfireman0905.gs
*And in the cab's config add this - note location in the file isn't critical but can't be within extent of another container:
*script "SteamCabinFireman0905"
*class "SteamCabinwithFireman"
*******Make sure the sound directory is added to the cab interior's directory*********
Post back if you need more help