One dealer had SFO 110's with 5160. A Buck knife with a carbon seel blade was never a standard production item (uless you count the beginning years when all the knives were forged from worn out files), or available in the custom Shop. (at least not in the Custom Shop since the move to Idhao in 2005. I don't know about the California Custom Shop).
As
jbmonkey
said above, in post number 5, that dealer is presently sold out of all the various 100 series knives they had with 5160 blades, not just the 110 and 112.
I asked them today, about the Buck SFO's becoming availble again between now and 2024. They don't expect to get any "in the forseeable future." "...Buck has limited production capability at this time." was the reason given.
(They are no longer a BF supporting dealer, so I cannot mention them by name anymore.)
Your best bet to find one is on the exchange here, the big auction site, or some other website that sells used knives. (there are several) Other options (please don't hate me for mentioning them) is getting a flint and steel like was used before "Ferro Rods" were invented (available on several websites, with or without kindling/char cloth/natural cordage) , a BIC or ZIPPO lighter, strike anywhere matches and a match stick safe, a magnesum "forever match"... the bow and string like you used when a BSA ...
Truthfully, a lighter or matches work a lot better than any ferro rod or flint and steel. Do you
honesly think the boyz 'n gurlz "back in the day"
wouldn't have used matches or a lighter if they had been invented/available?
FWIW, stainless with a 90 degree spine will spark a Ferro rod. Look at how many SS knives are sold with one (with or withut a suitable spine angle), and not just the MilTec, Tac Force, Master, made in Pakistan Frost, and other low quality fantasy mall ninja wanna bee knife and
"WTF IS THAT?!?" shaped objects.