Installed additional oil tank mount bracket, in accordance with SB 13-04-05. It took under an hour of work once I'd understood exactly what was required. Very simple job, made easier because I do not yet have anything installed on the firewall so access was not a problem. Drilling the aftmost inboard hole was tricky as the fluid fitting on the firewall shelf gets in the way of a normal drill. A right-angle drill would be ideal here, but as I didn't have one, I just did the best I could with an air drill - the hole came out straight enough to accept a rivet so I'm happy with that!