The chances of getting new aerial plugs are pretty small.
You could cut the plug off the aerial connection to the amp and fit a female to
wire that goes to the radio and connect the new roof aerial wire to this
connector.
As the aerial amp connector to the side window is very small and a male part to
plug would be near impossible to find I found that buying a aftermarket
aerial amp is the answer. This could be mounted at the radio end of the cable
Pull the roof lining down a little and mount the aerial as shown.
It takes a bit of courage to drill a hole in he roof but just mark the position
very carefully.
Dave T