I would put a slightly different spin on things.
If "originality" is important to you, then go for alloy every time, but best see the bank manager first as the cost is going to be eye-wateringly expensive. Restoring your current alloys may be similarly expensive, it just depends how bad they are , and whether you are able to get them to a really skilled panel beater/aluminium welder who is familiar with Morgan wings , there aren't too many of those around.
If you use the car in urban environments where parking knocks are commonplace , or use the car is any sort of competition where an occasional "ding" is inevitable, then go for fibreglass every time.
