quickbooks pro delimma

[pamo]

I have an art gallery - wheer all the sales are consignment.

I have a horrific mess in my quickbooks from creating a gazzillion 'inventory' part numbers that should have been 'non inventory' part numbers.

So I have 6 year worth or mess on my COGS and don't know how to fix it.
I need to somehow make credits for the actual checks I payed the artists.

In doing a lot of web searching I discovered that had the artists (ie part numbers) been 'non inventory' - this would have worked when I wrote the checks.

But, I cannot go back now an re-do it.

Can anyone help?