The few aerosol coatings I've looked at offered 'some UV protection'. I wasn't impressed.

I suppose framing them isn't a goal. Perhaps you could rig up some sort of display where they are held with mounting corners as simply as possible. Then you have options for covering them.

Regular glass filters about 43% of UV shorter than 380 nm.

'Conservation' types of glass filter a minimum of 97% <380 nm.

'Normal' acrylic, which must be made from gasoline judging from the price increases the last couple years offers ROUGHLY 70% UV filtering (this may vary from mfr to mfr, as it's not a guaranteed parameter).

'Conservation' acrylic claims 98% UV filtering, with slightly differing spectral properties (filters <400 nm, slightly into the visible blue spectrum).

Unless you happen to have happen to have the acrylic available to you, the cost, 'scratchability' and higher static charging than glass are disadvantages. Impact strength over glass is improved, and you could even screw a piece of acrylic over your own frame construction, avoiding the cost of custom framing.