If you want tanks and you're already in the general area of Oberndorf, the Schweizerisches Militärmuseum isn't too far by rail. It's in Full-Reuenthal.
Pretty good displays, including a Tiger II if memory serves. Their small arms collection is also pretty neat, but be ready to see some stuff that's mislabeled. I seem to recall a Gew41(m) that was mid-ID'd as a 41(w), for example.
Very nice museum! a must see if you are a Mauser or HK lover. lots of unique things to see!! also Simon the conservator is a nice guy always willing to help you.