Another minor correction...

Under this part, the address in the router config should be .200:

! Use NAT to expose JUST the web service on PC2, 172.16.0.200, as 99.1.1.3:
    ip nat inside source static tcp 172.16.0.100 80 99.1.1.3 80

Like this:

! Use NAT to expose JUST the web service on PC2, 172.16.0.200, as 99.1.1.3:
    ip nat inside source static tcp 172.16.0.200 80 99.1.1.3 80

I didn't see a way to edit the original message. If there is a way, please let me know and I'll fix it. Thanks