I live in Cedar Park TX and have stood amost in exactly the same place as you are standing in this photo. I started modeling about 1 year ago and fell in love with KATY once I settled on a RR and area to model. I'm modeling Taylor, Elgin and Smithville. Also saw the Mikado you modeled. Really nice job. I am looking for one with sound. Have LHS looking. Just saw TRIX model with humpback? boiler and was wondering if that was typical of MKT for their 2-8-2's.
If I recall correctly the TRIX steamengine boilers were all what was called Belpaire bolilers or fireboxes. The PRR and a few other railroads used them but not the MKT. Any of the USRA type boilers found on Kato, Model Power and many Atlas/Con Cor/Rivarossi steamers would be closer starting points to model the engines that ran on the Katy.