The older invoices I have been placing on the IPDB when I encounter them:
https://www.ipdb.org/search.pl?images=invoice&sortby=date&searchtype=advanced
Is any of that interesting to you?
If you email me a scan of your invoice, I can place it in the listing. I can/will redact any personal info, or you can do that.
What may be meh today, may be interesting tomorrow.