I think the reason that so many Bengals were used with Servals in the beginning has as much to do with the fact they were a wild-looking spotted cat as the fact that most of the breeders interested in growing up a Serval with domestics were already breeding Bengals, so could select the girls to grow up with the Serval from their own cats... which they would have known if any carried a little longer, if they were from healthy lines etc.
The official outcrosses for our breed were selected for type though, there was discussion on which breeds would help the development of the Savannah breed the most. Not sure if that was part of your question as well. But in terms of what they put with Serval it was less about what was considered permissible and more about what the Serval wanted too...they found that Servals actually seem to prefer the Bengal girls over the plain domestics for example...and that some were rather bigoted and would only breed BSTs and avoid the silvers and the solid blacks!
I only got my first SV in 2001 and joined the lists shortly after...but when I decided to breed in late 2002 (I spent a year researching before we actually brought our first girl home) I went to cat shows to talk to the breeders that were active back then. I was lucky enough to get great mentoring from a number of those original breeders so learned some of the breed history at that time.
The official outcrosses for our breed were selected for type though, there was discussion on which breeds would help the development of the Savannah breed the most. Not sure if that was part of your question as well. But in terms of what they put with Serval it was less about what was considered permissible and more about what the Serval wanted too...they found that Servals actually seem to prefer the Bengal girls over the plain domestics for example...and that some were rather bigoted and would only breed BSTs and avoid the silvers and the solid blacks!
I only got my first SV in 2001 and joined the lists shortly after...but when I decided to breed in late 2002 (I spent a year researching before we actually brought our first girl home) I went to cat shows to talk to the breeders that were active back then. I was lucky enough to get great mentoring from a number of those original breeders so learned some of the breed history at that time.