What kind of safety glasses/goggles do I need?
Something like a valence would work - something on either side and a decorative piece to cross in front of the actual bell head or whateve the alarm looks like. But realize that many of these fire alarms are also the fire detector and your cover could interfere with the function of the detector or deter you from keeping a fresh battery in there by being hard to open. If you have made it hard for a smoke/fire detector to function, some insurance policies will not pay in the case of a fire.
pay back your dad when you have the money and keep them both