Export SSH Private Default Key from Serv-U for OpenSSH DR server

I have a production server where a lot of clients have memorized the key signature so we can't change it.  To the best of my knowledge, this is a default key, not one we manually generated or anything, but it was done by a former employee many years ago.  (No way to contact them anymore.)

The key is RSA, encrypted.  I can convert via OpenSSL commands...but where can I find what password Serv-U used on this key?  Its obviously stored somewhere because Serv-U can decrypt it and use it.

What should I be looking for?  I want to have another server configured (non Serv-u) for DR purposes.

This is my key, my signature...but I cannot find any information anywhere on how to gain access to my own key.  Is Serv-U keeping my key hostage?  I spoke to friend/associate at another company that uses Serv-U and they said you refused to help them when they contacted you, claiming that you would not reveal the password used to encrypt the key.  Is that true?