I don't have any consecutive serial numbered guns.
I see them here and there for sale and they command a premium.
I was told once that if they were ordered that way and you could prove that they were ordered that way, then that would be unusual and worth more. But to just find two guns randomly and notice that they are consecutive is not really worth a lot more.
I've attached a Ruger Brassie Photo to spice things up.
"But to just find two guns randomly and notice that they are consecutive is not really worth a lot more."
If the guy buying the pair thinks it's worth a specific amount, then it's worth that amount. Buyer derermines "value" every time, particularly in a collectible market.
And actually, the remote chance of pairing up two, or even three or more guns on the open market -- particularly Old Models -- would seem to add a considerable "rarity" to such a score. It certainly would to me.