Seven Valley Sailplanes in the Uk made some, done as a British Gliding
Association major mod about 15 years ago. It was not a factory TN or EASA
Mod

https://www.svsp.co.uk/about-us/

They don't do sailplanes anymore but you could always ask

Assuming you are US based i guess you could use them if your airframe is
Experimental

Pete

At 12:56 15 August 2020, ZCHRL4 wrote:
Anyone out there know of a retrofit winglet set for 303s???
Thanks!

Nick L