All I know about Sandtoft is that it is inaccessible by public transport !
Difficult but not quite impossible - see
((here)). Been on my list of "places I want go to sometime" for some time.
By Bus
The only public bus service in the area is justgo North Lincs which runs out of Scunthorpe on weekdays and Saturdays. Journeys have to be pre-booked and there is no Sunday service. Details can be found on its website,
https://www.justgonorthlincs.co.uk/Every Saturday the Museum provides a connection to public bus services from Doncaster at Thorne; click here for details.
On Sundays marked "Free Bus" in the Events Calendar and Bank Holidays we run a free bus service from and to Doncaster Interchange and details can be found here.
Please note that the Museum's buses are historic vintage vehicles and have step entrances.