Show a profile view of the cut end of the trim. Looks like a sprung bed moulding but the size is awful small

I'd take a piece to my local, professional lumber store. The ones in my area a large variety of molding in stock and have catalogs with lots of others you can order and get within a few days. Some specialty shops will cut a molding knife that matches a unique profile and mill whatever you need...but it won't be cheap.

That is called 'glass bead moulding'.

We need to see a cross section to know what the profile is.

Here is one:

https://www.homedepot.com/p/Kelleher-1-4-in-x-7-16-in-Pine-Glass-Bead-Moulding-P456/100321663

ETA: Don't sweat the back side. You can easily relieve a 90 degree molding with a small hand plane or belt sander.

If you need an exact match you can try Anderson-McQuaid in Cambridge, MA. They have many thousands of profiles available and can make a custom cutter for your profile if you need it. Not cheap, but a great source when you need to really match something.

Assuming you don't find an off-the-shelf match and If you have a shaper the easiest DIY solution is to get an Amana insert cutter and grind the profile you need on a blank insert. For a short run you only need to carefully shape one cutter, the other side just needs to balance and be set short of the one that's doing the cutting.