Looking for one of these with the spring loaded pin. Nothing I can find on ebay or secondhand yacht parts sites. Not made anymore by Ronstan - their biggest I-beam track these days is 32mm (inch and half is 38.1mm).

www.deckhardware.com.au/Adjustable-Track-Stop-1-1/2-38mm-Traveller

I mean, 275 bucks is taking the piss for sure, but somebody's making them....

Not sure the Schaefer stop will work on the Ronstan track. I think they have different stop pin sizes - half an inch for Schaefer, 5/16 inch for Ronstan, Also somewhat different track cross section, even though the width is the same.

Can you provide a photo of the track ? You see 2nd hand deck fittings like that come up quite often on Facebook market place.