Hi,
I hope all is well. I can provide you with a CSV file (or Excel file) with the links which I will crawl from your sites. I'll be happy to provide you with a sample of one website beforehand, as per your description.
There is one thing, though, that I would like you to clarify. You mentioned you would like a CSV file with both the old links and new links. How would I be able to get the new links? Is there a pattern to convert the old link to the new link?
One thing to note is that seeing that there are about 6000 links involved, this means you will be getting around 6000 requests from me (in addition to your current traffic). If needed, I can adjust the rate I'm crawling your sites to prevent your sites from getting overloaded, however, the slower I need to crawl your sites, the longer the delivery time will be.
Feel free to ask me any questions you may have.
I hope to hear from you soon.