Yes, guides for our disabled guests are free and available anytime from guest services.
Keep in mind, that unlike many of the "older" queues as Disney, almost ALL the queues at Universal were built following the guidelines set forth by the Americans with Disabilities Act (ADA). In other words, ALL queues (except Kongfrontation and Back to the Future) accommodate wheelchairs. So be prepared that you and you hubby will need to wait in the regular queues with all other guests.
The only issue that may come up (and is not listed yet in the Disabled Guide) is that some Universal Express queues are not wheelchair accessible (Hulk, Doom, Ripsaw, and Cat in the Hat come to mind). Although you will still need to obtain an Express ticket and return at your scheduled time - you will be directed to a different entrance to accommodate the wheelchair.