More on the shower tanks later, however I would NO use a tank that had been used for pesticides or fertilizers... (I did reuse on that was for cleaning solution as I figure SOAP will clean out completely...)
The rest of the Tub Tools:
A fair number of Wrenches. So who knows what a 41mm Open would be useful for?

and there were 2 of the pin spanners, of different sizes... (I found #2 after the pic)
Sockets (2 Craftsman As set of Husky USA, and a few Taiwan), An 80 ft lb torque stick, Bits, files and rasp, Plumb Hammer, tapes, & chalk lines
Upholstery mostly; the staple gun is a cheal POS. adn probably uses desk staples.
Drivers, agian a bunck oif chicom not shown adn most al on the right are giveaways, to those that might need them.
Cutters, compound Wiss shears, pruners, wood chisels etc. Cheap staple puller, NOS Spark Plug gap gauge.
Lots of Pliers; some were Chicom and went into the "sell this **** cheap at the next yard sale" bin. Two of the strippers are Klein adn Amp, others are decent to good.