Tracking alt inventory?
Write it down.
EDIT: I have seen an interesting way to do it within the game, though. There is a system for keeping track of players via "notes" that you write, /playernote.
You can create playernotes for global handles that don't exist, and keep track of stuff there:
/playernote InventionSalvage
/playernote InventionRecipes
/playernote InventionEnhancements
etc.
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Oh, that's... that's evil. But brilliant.
I sooooo miss WoW's lua-based interface with well-supported user modifications.
I have a big *** Excel Spreadsheet, where I track almost everything.

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I have been running into the same thing so I created an Access database which I have forms setup in to enter salavage and recipes and working on making it so I can know what salvage pieces are needed to make each on.
The basic sense works but WOW is there a lot of salvage and recipes to enter. The basic data entry for the database is a PITA.
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Arc 139668: Bob's Crazy Car Dealership
I track the stuff for making the 10-50 Common IOs. For Set IOs, I use All Star's Recipe Cookbook (which I still need to update to the latest version... >.<)

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The database I have been working on will have all of the different requirements for Set IO's and also allow me to track which character has the recipe/salvage.
So far the part of what character has the recipe and salvage is all done and just trying to make it so I can run a query and know which characters have the pieces I need for the recipe I have.
I just wish I was better with databases.
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Arc 139668: Bob's Crazy Car Dealership
Good luck. The only database I'm familiar with is My_SQL, and accessing it via PHP.

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I assume this is beyond the scope of what can be done in CoH, but maybe not. I am unable to remember which of my alts have which items either in inventory or in vault reserve. Is there some convenient way to have this information tracked or recorded, or do I just have to do it myself?