Back when tanks were made with thicker glass, they didn't use a brace, I have a 150 I bought in the early 80s without a brace, it's still up and running. It's one pictured in the chipped thread.
Yes, if it had 5/8" glass, it would have a serious problem being 36" tall. That's not close to the correct thickness. At 28-29", 5/8" makes perfect sense.
Wow no one reads anymore. Op has 2 posts saying that the guy he bought it from said it was 36" tall, but it was actually 30" tall making it a 220.
Awesome pick up, keep us updated with some pics!
I agree that if the tank was designed without a center brace, it should not need one.
Have you already done a leak test?