Due to issues with suppliers, I've started molding my own urethane rubber Spyder-style 'nubbin' detents to fit my Automag to Autococker barrel adapters!
These detents should also fit a wide range of Kingman Spyder markers, the McDev Clone, older Intimidators, early CCM T2 pumps, Piranhas and I think most Azodin markers.
I figure $1 each, and I can stuff quite a few in a $2 First Class mailer. If you just need enough for one marker, how about a 3-pack, shipped, for $5 even?
I have a couple dozen on hand, and more on the way. If that 3-pack works for you, just PayPal that $5 to firstname.lastname@example.org (please include your mailing address and what the payment is for) or hit me at email@example.com for larger quantities or Canadian or overseas shipping.