Several years ago I obtained copies made from exterior blueprints for a three-bay Texaco station.They were dated from January 8, 1959 for a project to be built in Corpus Christi. They have all the dimensions for the building on all four sides, which is just what you'd need to build one in scale. I scanned the copies and made them as readable as possible, but the files are very large (8 files @ 7 to 10 MB each) so I can't post them here, so I made screenshots:
Now if these aren't readable enough, let me know and I can email the original large files to anyone who'd like to build one. The original blueprints were sold in an eBay auction; I got outbid but contacted the seller and asked if he would sell me some copies. He made them and sent them to me for free! So this is my way of paying it forward. I wish there were interior measurements as well, but hopefully you can guesstimate those.
The building itself looks to me to be nearly identical to the Buddy L kit with one more service bay; I imagine you could tweak the measurements to make a one- or two-bay station. Happy modeling!
P.S.: This former station in South Carolina is very similar except for the canopy:
http://forums.aaca.org/attachments/f169/11487d1181336318-ghostly-gas-stations-442242-texacoonebay.jpg