Thanks to Nathan discovering that the Internet Archive (A great resource for a lot of historical stuff, not just BH research.) had post-1923 Engineering News-Records, I have discovered that the Jayne span lasted all the way to the 30s.
However... This Jayne span matches those at Betram.
Jayne was notorious for rebranding Stupp spans, and they don't match Stupp's designs AFAIK.
Thanks to Nathan discovering that the Internet Archive (A great resource for a lot of historical stuff, not just BH research.) had post-1923 Engineering News-Records, I have discovered that the Jayne span lasted all the way to the 30s.
However... This Jayne span matches those at Betram.
Jayne was notorious for rebranding Stupp spans, and they don't match Stupp's designs AFAIK.