Hey Bradley, I work primarily as an insurance broker in SF. I can assure you that if the property is as you've described the premiums will be higher than usual. My suggestions would be to find a broker who can market your house to surplus lines vendors as admitted companies in FL are probably charging you an arm and a leg. You should keep shopping around, be wary of low premiums on the front end, then an additional premium once the company does the home inspection. Let me know if you have any questions, would love to help.
I'd suggest getting the property re-quoted from the same agents as if it had a new roof while getting quotes on replacing the roof. Then weigh the cost of the new roof versus the cost of the more expensive policies and see which makes more sense. If you will pay an extra $2000, or $? more per year for the policy versus a 1 time hit of $10k or $15k for a new roof it may make sense to get the roof done. Ex: $2k extra per year on insurance>every year< vs $10k for a new roof is a 5 year break even in my opinion. If you replace the roof then in year 6 the savings on insurance would drop to the bottom line.
Roofers can vary ridiculously on what they charge and the cheapest is almost never the better option. If it's a cement block ranch like a zillion other SF 1925 built homes you have a low roof and easy pitch which may be pretty easy to replace. If you find a one man handy man who can do the job and you personally put a couple weekends in helping him you may be able to do the roof yourself for much less than you are getting quoted.