Very sorry to hear about your dad. I bought I tegu from him in 2001, which is still quite healthy today. Bert was so knowledgeable and so quick to get back to you if you had a question. His unique approach to herps really made him stand out, I still have old Reptiles and Vivarium magazine copies from the mid 90's I bought just because of Bert's articles.
Herptoculture has lost a giant. I may be a bit biased, but to me Bert will always be THE lizard man. R.I.P.