sorry for your loss
I have a help 'em up harness. funny enough I had JUST bought one for my older lab who is having mobility issues (rocky is 12) and I have lots of stairs here. Shortly after Penny blew the knee and I was luckily able to borrow the one she is using (they are not cheap!) It is a great harness. Super useful for Penny. I use a regular leash and loop in in the back handle and clip it to the front clip so I can control her movement and support her back up. I can also use it to just navigate her from the x pen to the crate and such.
Help Em Up™ Dog Harness | Hip Dysplasia | Dog Carrier
We hit some snags in recovery, it hasn't been as clean and straightforward as others but not crazy bad as some stories either.
For the ramp, did you try using treat trails? Rocky (my lab) has been iffy about the ramps here too, he now seems to mostly use it to get out but steps up the top of it to get in. will need to work on him. Penny never had much of a choice as I am holding her harness and walking her up and down.