I have not used it, but the AMD website still has a page for 500 series mobos and 5000 series cpus for a loaner. https://www.amd.com/en/support/kb/faq/pa-105
You could try this from Amazon for $11. I purchased a 46w charger from the same brand and it works fine. Also comes with a usb c to usb c cable as well so that's a bonus. Free return if it doesn't work for you.
You will want to double-check, but looks like this one may work. $8 from Amazon.
https://www.amazon.com/Adapter-Pavilion-EliteBook-Compaq-Probook/dp/B078NS61BH/ref=sr_1_14?ie=UTF8&qid=1547662440&sr=8-14&keywords=463958-001
I have an old 6600gt laying around, you can have it for just the cost of shipping. has not been run in many years but I can try to test it if you want it