Baggage area tie down upgrade?

[Robm]

I have a new, to me, 78 m20j. The baggage area tie down has some old straps bolted to the floor with a ring that is pressed directly into the floor.

seems to me I would be better off using my own new straps connected to d-rings that I can actually connect to. Sadly the rings are bolted to the floor and I can’t change the straps without loosening the bolts 
Is there an approved stc to replace the default smashed down ring with anything else that can be connected to decent straps? And may offer more utility? can I replace them as an interior owner modification?  

thanks for any suggestions,
 

[PT20J]

The D rings just attach to a bracket that is screwed to the floor with an AN-3 bolt. You could just remove the bolt and ring and replace it with something else. I always liked the straps Piper used on the Cherokees. There are some for sale on eBay. You'd have to talk to your A&P and see if he agrees it's a minor alteration.