I was only there a few months ago, and he was giving tours of the Colossus (and he looked great - would never have known he was 80). This is such a shame.
I think they're doing a bit better these days. They were able to get some lottery money to renovate the mansion, and Google has made a few prominent donations this year.
The main problem is that the site is so large and most of the buildings are just cheap, unmaintained concrete shells that weren't intended to outlast the war. They might have been better off demolishing some of the less important buildings so that they could focus on the remaining structures of historical significance.