Congratulations on finding your Tundra!
I bought a brand new 1st Gen Tundra AC, SR5, TRD 4wd in 2000. Trouble free except for a bad intake manifold and the infamous rusty frame.
Loved that truck but after 14 years and 180k, I had to make some hard decisions. The frame condition scared me. The transmission had me worried too, as the early Tundra's had a reputation for A340 failure at ~150k.
I posted it FS on CL, and it was sold in less than 4 hours.
The guy who bought it was looking for exactly this configuration, and dropped everything when he saw my CL post.
I believe in full disclosure, and told him the reason for selling. He looked at the frame, and said he could fix it. IIRC, he was an engineer and professional welder.
Hopefully that truck is still on the road. I do a double take when I see one, thinking it may be my old truck.