(New member here.)
I don't usually necro-bump old threads in forums but in this case I thought it was worth mentioning that I also found HDF on Amazon's Smile program.
If you shop on Amazon Prime a lot like I do, you can support HDF by setting your Amazon Smile Charity to "Hawaii Defense Foundation" and Amazon will automatically donate 0.5% of your purchase prices directly to HDF at no extra cost to you.
To set HDF as your charity of choice, simply go to smile.amazon.com and it will prompt you to choose a charity of your choice. Just search for HDF and it will come up.