Great idea of Gwalior-Porbander train. Such a train can also run via Gwalior-Guna-Kota-Vadodara route, instead of going via Guna-Maksi-Ujjain route.
Another alternate route: Gwalior-Guna-Kota-Chittorgarh-Udaipur-Ahmedabad(Th is would be after Udaipur-Ahmedabad gauge conversion).