The site is hosted on Classic Google Sites, providing an IP address doesn't make much sense, since it's aliased via a CNAME redirect which changes for each visitor - pointing at ghs.googlehosted.com.
For example, for me right now its: 188.8.131.52, for a network based NSLOOKUP it's: 184.108.40.206
I am the owner of the domain, the sub-domain and the site, as well as its author.
The report came in via one of your users who also tested three other sites, one on the same domain, running New Google Sites, one using a different domain, running Classic Google Sites and one running New Google Sites on a different domain. None of those returned a "Website blocked due to reputation"