Glad you're back on the road. If it was mine I would look inside that tank, acid washing scares me. If it's just washed future rusting could be an issue as acid cleans old rust it exposes more raw metal to air. Some of the restoration gurus here talk about sealing the tank, I've never had to do one but if it's sealed it'll stop rusting. They can put a name on the products used.
As far as your comments on this site the $12 a year has saved me untold headaches and $$$$ in repairs and maintenance.