Result - Pulled out the cylinder per the video above (super easy) and took it to the local locksmith in Torrance yesterday evening. Old school Japanese man in his 60s that I'm sure has been doing it most of his life.
He said the key and tumblers were worn and told me to leave it with him for half an hour. He made a new key (cold cut?, I believe) and rebuilt the tumblers inside. He did say there was some additional wear to the cylinder internals and it would have been ideal to have a new one, but this should get me by for some time. Because of the extra wear internally, the new key he made was slightly stepped up from the one I provided. Even the door locks work smoother now with the new key. I'm actually embarrassed to say how little I paid for this.
I appreciate the advice and detailed guidance here by everyone. I'm sure RagingMatt's service is excellent and is definitely the Toyota method, I just needed minimal downtime and this was the solution that worked best in my situation.
P.S. - when he gave it back to me, he asked what kind of Toyota it was for then lit up when I told him it was an old Land Cruiser. This led to a 10 min conversation about people he knows who have them, their off-roading expeditions in SoCal, and the sense of community a lot of the owners have.