On One Pompino owners...

For some unknown reason* even with a 103mm BB you have to run the chainring on the inside for the messengers to get a 42mm chainline. From memory the outside gives 45mm. Most track hubs give a 42mm chainline.

Sheldon is good. You should also look in mech & fixing on here. There is a sticky for good websites.

*probably because they're just road cranks.

Inside is good, means you can put a guard ring outside