I have visited this museum 6 times over the last 10 years and each time there is something new.
To give justice to the amount of exihibits you need at least 1/2 a day.
Not only does it have internal historical displays but there is also an underground mine, outside train display and so much more.
I have seen a lot of museums in the 37 countries I have visited and I can honestly say this is the best local history museum I have ever seen.
Whats more is that Zeehan is central to all the west coast and has real cheap accomadation (especially compared to Strahan).
So you can base yourself here and its only 30 minutes drive to anywhere in the West Coast.
The only down side is that part of the museum is on the first floor and there is no lift.