When I first moved to the lake area I believe the depot was still at the corner in Mabank. I don't recall when, but it was moved west along business 175 across the street from what used to be the combined Mabank High School & Mabank Middle School. It was then turned into a cafe. In more recent years it was used for housing.
A bank now sits where the depot was originally corner of Business 175 (Mason Rd) & South 3rd Street (198/FM 90) The bank's website even claims "Our bank in Mabank looks like an old train depot and sits on the site of the original Mabank Depot."
It's not part of the cache, but if you have time perhaps drive east to the corner to see where it was originally.
(yes, we probably should have made this into a multi or puzzle cache, but didn't think of it until now at home 
)
***** Congratulations to TeamOxford & drives for being the co-FTF!! *****