Been reading Jon Peterson's new book Game Wizards on the business history of D&D/TSR (which I cannot recommend enough for so many reasons related to this forum) but I saw this post on his blog with a brief history of how Arneson did hit points vs. what Gary did:
http://playingattheworld.blogspot.com/2 ... cters.html

It's mostly stuff we already know from memorizing FFC, but I hadn't heard this one and want to try it next time my group goes for something "Arnesonian" next time:

Roll 1d6 and then roll that number of d6s and that total (between 1 and 36) is your starting hit points, which never increases for the rest of the campaign.

I don't remember that, but I didn't create a new character until after D&D was published, so I used those rules when I did. My initial character was on an index card that Dave Arneson created and kept. I rarely even saw it, so I couldn't even tell you how many HP my Svenny character had in the early days.

I haven't read the blog post and am generally avoiding Mr. Petersons work as I am engaged in my own research. However, it is not surprising that Greg doesn't remember the method, as it is not something they ever actually did in the Twin Cities when playing Blackmoor. Arneson proposed the idea to Gygax for D&D, and Gygax rejected it in favor of the method we see in the 3lbbs. Arneson later mentioned it as one of the things he would have preferred for D&D in a leter published in the GPGN. I'm sure that was mentioned in the blog.

The general idea was recycled for Adventures in Fantasy, except the range was extended and tied to a formula.

If you would like some more thoughts on Arneson and HP I have a 'blog post