Here's the best way to find the toolbox. First, stand on the bridge leading into Lakeshire. You'll see a patched, wooden part of the bridge*- stand on that and jump off into Lake Everstill below - jumping off the east side of the bridge into the water. Swim east and look underwater - beware of level 18 and 19 murlocs. As you swim east underwater, you'll come to a sunken rowboat. Keep swimming past it to the second sunken rowboat, and you'll see the chest on the bottom of the lake by the second sunken rowboat. So basically, jump east off the Lakeshire bridge and swim east, watching underwater for murlocs and the first then second sunken rowboat, and you'll find the sunken chest that contains Oslow's tools there on the bottom near the second sunken rowboat. Good luck!

*note - the wooden patched section of the Lake Everstill/Lakeshire bridge I am talking about is the small patch that's closest to the south end of the bridge & the Redridge Mountains- not the wide wooden section of the bridge closest to Lakeshire. Right when you're first starting to enter Lakeshire, coming in from Redridge Mountains, that southern end of the bridge has a small little wooden patch on its east side. That's where I'm talking about.

At coord (41,54) - above the first 'L' in Lake Everstill on the map.

Leads to The Everstill Bridge
https://vanillawowdb.com/?quest=89 https://vanillawowdb.com/?quest=89