With a 40 for day 1 and a sub 2min day 3 I'd say you pretty well own level 1. I'm no expert but chances are you are probably in good enough shape to be at Level 3 or 4? If I were you I'd try D3 of level 3 on an off day to see where your time is there and use that as a judge. I think you could get a sub 5 min L3D3 if you break the pull-ups into manageable sets. You should certainly be at Level two, but I suspect even higher than that based on the numbers you're posting. Give it a shot, it can't hurt to find out, and you can still stay at a comfortable level even if you do make it in sub 5min.