OK, so using the keys on the Sargent page as an example, and the choice of some of the keys are very popular or the choice of most of the keys are not very popular:
What Sargent keys would you normally stock? The 5-pin 1007LA or the longer 7-pin L1007LA so you could cut it down to the 1007LA or O1007LA?
Or would you stock the 1007LD or the L1007LD to handle all nine keys from 1007LA to LC and up toL1007LA to L1007LC?
When would you NOT want to use a submastering or mastering key for cutting for someone?
I'm still very much a noob on this and I want to make sure that I'm not getting into trouble for getting a key and using it for a customer. I'll have to ask my vendor when I go in to pick up some keys tomorrow.
Part of getting a code cutter would be that I have a number of mailbox locks from mailboxes I picked up at an auction that didn't have keys. The cost to code cut all these locks to get a single key to use each, if done by someone with a code cutter, would equal about a third to a half of the cost of the code cutter.
So, justifying the cost of the code cutter is partially done on economics. If I can get my mailbox customer to turn me into his code cut key supplier, then it just adds to the justification, and gets me another toy to play with.

Are you a locksmith or just know a lot about keys?
Thanks for the lesson. I eagerly await the next lesson in "Your Key To Cutting Success" from Dale Harris.

BTW, any problem in showing the KEYFIND program to my key supplier? I know they have a subscription to a key display/information database that they get every month or quarter with key updates, changes, etc.
Reginald