Hi Carmac, and welcome to the board!
There are a few options to pull those messages yourself. If you set up Level I Unified Messaging on a mailbox, then any VMs left at that box will be emailed to you in a .wav format. You can then forward the existing messages to that box. Some people use the record a call feature and simply playback the message with RAC turned on and that will email the message as well, but that seems a bit redundant.
As for the converstion utility, since it's the actual Inter-Tel software we can't email it out as it's proprietary. If they want to have a conversion done we can refer you to a tech who does them.
There is a way to convert them with some off the shelf software, but I understand it's hit and miss. I've never tried it personally as we use the Inter-Tel tools.
Mac will be back in the office after lunch and he may have some added insight.