I think the best solution is make those not paying up front, pay a much higher amount after the fact. 500, 1000, 1500...whatever is appropriate. I'm sure placing a lien on the property is easy since they do it anyway for taxes and other matters. You could even tie it to any insurance payout and have it included in insurance policies. (Most policies have have mandatory requirements for coverage if there is a loan involved, so I am assuming these properties had no mortgages).
I think sending the same 75 dollar bill after the fact, does no good as nobody would pay up front. So you discount those paying every year, by having it 75 dollars. And then charge appropriately for those not paying up front. And if they don't pay for costs incurred in saving the property, you can't get a building permit to rebuild or allowed to sell the property till it's paid.
Personally, I would just rather have everyone pay a small tax for such services. And forgo the processes and even legal matters of another approach. But if you don't tax everyone, then at least have system in place for those that would not, or could not, pay ahead of time. Nobody should be without fire services regardless of the system in place.