VRF stands for Verifiable Random Function. It is the key essential to the lottery that your node performs. It is also an input to the pool’s registration certificate. I’d think, if you now sign a block with a different vrf.skey as recorded in the pool’s registration certificate - that this would be an error condition.
Don’t you have a backup of the original vrf.* key pair? If not, you might have invalidated the pool registration because you may no longer be able to sign the blocks that your pool mints.
I also don’t think that there is a way to resurrect those keys.
Please don’t take this as the ultimate truth. You may want to get confirmation from the core team.
If you have a backup, it should be sufficient to restart the block producer node with the correct keys+cert