I leak tested my left tank today.
Good news: I only had two small leaks in the lower corners just forward and aft of the tank attach bracket. An easy fix with a bit more sealant.
Bad news: I began mounting the tank on the wing and got all the bolts in and torqued before noticing that I need to file the inboard edge a bit where it abuts the leading edge skin. All those bolts have to come out. Argh.
Could be worse, but still...