I'm so sorry, Kat Scorp! And yes, the copper or tan colored doxies are called "reds" here for some reason. I had a tan doxie - Cappuccino - shortened to Cappy when we got her, unless she misbehaved - growing up that lived until she was nearly 19. She sounds a lot like yours, able to jump high and support her weight on her back legs. She used to beg for scraps by standing on her hind legs with her paws up in a position we affectionately referred to as The Squirrel. My mother still starts ugly-crying if you mention her, so I know it hurts no matter how long it's been The sadness and grief of losing a pet is one of those things that you can't properly convey to anyone who hasn't experienced it. Nothing rouses my sympathy more than the mention of a deceased pet, so your post made me want to cheer you up. I actually started to write a long post about losing one dog when she was quite young, and the perspective it gave me when Cappy died later that year, but I realized that would probably just bum you out instead.
Bu the point was basically that I think it's always easier to accept the loss of a pet when you know you gave them your all. Sixteen years for a dachshund is a nice, long life and it sounds like your Sir Henry was very, very loved. The dog I lost too young is the one I can't think of without starting to cry, but thinking of Cappy only brings good feelings. Her name is tied up in happy memories and I just feel lucky that I had her. It'll always hurt a little, but I think it helps that the sadness is for me because I miss her and not for her because she missed out on something. Her life was as long and healthy as we could ask, and she was happy and loved every minute of it. It sounds like Sir Henry was too.