Thanks everyone! I started with a 460 and 201 but the 460 wouldnt stay running more than 20 seconds... I switched it out for a 660 with a 20" bar and then after I got the big block (foot rest) out I was making a plunge and the sprocket disintegrated and fell out of the saw in 3 pieces. I finished it off with the 201, which was a chore.
After planing and sanding it the best I could the client informed me that while she was happy, she was disappointed that it wasnt 100% square with NO bypass. I am not sure who set up her expectations, but I tried to explain that with a chainsaw sunk 20" into a log, that the process wasnt exactly 'surgical'.
I was really pleased with how it came out, especially since it was my first attempt at anything like this, and I only had one shot.
I timelapsed the whole thing with some helmet cam footage, when I get it edited I will put it up.