Nice fish Schoolie Monster. Thats a beauty. I don't know about circles with eels. Not for me. I like a big gap on an eel hook. For a circle hook I'd probably want 12/0 to get the big gap. Stick with Live bait hooks. I believe Slipknots fork length was 431/2 inches. What was yours?
Tape measures don't need calibrating. This is an example of why scales should be calibrated. I doubt that fish lost that much weight.
Most of the scales used to have a calibration adjustment. If you can find a certified weight , you can pick it up and dial the calibration screw til the scale reads right. I have a fifty pound spring scale and may get it calibrated at work (NBS traceable). We could then use that to calibrate other peoples scales if they like. Or maybe I can get them to certify a weight for me and people could pick that up at one of the next two legs and either calibrate their scales or at least get an offset which is added or subtracted to get the correct weight. Anyway , I'll see what I can do. I still say tape measures need no calibrating.
Congrats on the fish.