Has anyone seen this style of skylight? If so, what approvals if any are there? I have the Crosswinds and Atlee skylight STC but neither look like this.
Once I get my ducks in a row I'll start a thread for this project.
Looks like classic X brace with standoffs. Very common for older cubs to have custom tabs/gingerbread. Back in the day welding was a logbook entry only for many if even mentioned Standoffs and gingerbread seldom needed a pen to work. Check the logs and see if it was even noted. It can be an issue with the wrong IA. Looks like you are a bit down the road kind of late to change.
What are your plans for that short tube just aft of the X? If that is for a shoulder harness, you should review AC 21.34. https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_21-34.pdf
Look on page 26 for the angle at which the shoulder harness is related to the pilot's shoulders. Your attach point ought to be further aft.
The X brace looks fairly normal. The stand offs are different but they look fine. The short cross bar is where to attach tbe shoulder harness. Is it a Dakota Airframe? They're long gone. Univair bought them years ago. If it is a Dakota you may not need any approval. Their airframe was PMA'd.