They would in all likelihood maintain a listing here too, but if not your shares would be swapped for new shares listed on the overseas exchange. There is a cost for maintaining a dual listing, but the aim would be to add demand by being listed in a market that understands what MUS is doing.
The obvious location would be the LSE given that is where Gemfields was listed and there are plenty of ex-GEM shareholders that understand what MUS is doing.
MUS Price at posting:
8.5¢ Sentiment: Buy Disclosure: Held