Got the tote bag done! I'm very pleased with how it turned out - I'll transfer my stuff from my battered old purse over to the new one after lunch!
Some pictures, both in progress and complete, below the cut.
Here's a shot of the bottom of the bag, inside out, to show the construction:
Here's the bag right-side out, waiting for the zipper:
The top pieces with the zipper joining them:
The top pieces sewn on to the bag, ready to be pressed into place:
And here's the completed bag: