Did you get an answer to the above question on preserving the paint chipping? I'm making a headboard and have the same question because I want the same look.

I haven't done it yet, but below I'm quoting the 2 responses I teceived.. Hope this helps. If you try any one of them, pls let me know:
We sprayed it with Deft (laquer) in a eggshell shine. It kept everything intact

hard to do without changing the sheen or colors a little bit. I would experiment on a small section with polyurethane or maybe a glaze could work. (st..."

We have used a spray poly in satin to seal the chipping paint. Yes, the color & sheen does change a little, but it's worth it to keep from chipping any further. We just sprayed some vintage columns for our kitchen remodel, also.

I have an old fireplace mantle that I want to keep some of the peeling paint. A friend told me to mix wood glue and water to make a paint type consistancy and paint it on. Has anyone tried this? It taste like lead paint. Ha Ha

I think I just saw this mixture used on a peeling/chipping antique table of flea market flip. I am in the process of searching for the "recipe"