I have my 89 model insured with Global Aerospace.
My insurance is handled through Assured Partners, however I cannot say that they particularly favor insuring a Bellanca. I have been with them a long time and have a clean record. I am somewhat of the opinion that your quote will depend on the mood of the underwriter on the particular day that the request comes to them. Perhaps the most important factor is to find an agent that has a good direct relationship with the underwriter and be willing to offer an extended checkout with a qualified instructor (which is not a bad idea in any event).