Along with the Badger Bits C38 kit mentioned previously (now waiting for me to get to Brisbane and Horizon Hobbies to purchase the paint recommended by the Australian N Scale e-Group) I purchased the VR K Class kit as I had been on a trip from Lilydale to Yarra Glen with K 190 around the same time as 3801.
Like the 38, it is a resin casting to fit on a Micro Ace chassis. Unlike the 38, no mods are necessary to the chassis and the loco body was easy to clean up. Progress pic below, followed by one of the real thing I found on the Internet (Michael Greenhill's photo from Flicker.) I plan on making mine look like this, minus the sticker under the cab window so it is an ideal shot for inspiration for the model. I have thoughts on the motor in the cab but haven't explored options for making it smaller yet. Next step with the body is to drill out the chimney and then put on the brass etch detailing bits.