Severance offer, what should I ask for? after 12 years as a welding apprentice

I was offered 12 weeks of severance after 12 years as a welding apprentice, and I have a few days to sign. There is a non-disparagement clause. Did anyone negotiate and succeed?

I asked for two more weeks and a neutral reference. They agreed to the reference and added a week.

Read the release carefully. Mine included things I did not expect, like a non-compete.