luffmystuff 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..."

Buckets of Burlap 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.

tlmmommy I have 3 small kids and have purchased a 100 year old barn door to use as a sliding door with flat track hardware. Did not even think of the lead paint issue when buying. Being 100 years old, of course the paint is peeling/cracking and I love the character of the door and want to perserve that. Just wondering if painting a clear sealer over is safe enough with the kids. I guess if I put enough coats on it may work.

Lauri Nielsen_West Will the clear sealer make the wood appear darker and shinier? I still want the light gray dull look. Do you have a recommended brand or kind of sealer?

Buckets of Burlap Hey, we painted this room when we moved into our home in 2005...and we don't have a trace of leftover paint to refer to. I'm sorry, I don't remember the color of this paint...

ladypup Possibly Para Paints - Moselle or Cloudy Amber - both older palette but have used them to this effect in the past