Ian,

I did some testing a while back with pressure pack acrylic clears.  Albiet not on a playfield, it was difficult to get a really flat finish and flared up on second coat.  My biggest concern would be how durable it is with the ball.

Having done it on my FH playfield - I would definately go the 2k clear.  If you can borrow a good compressor and gun that would be the way to go.  Would cost less than $100 in materials.

I think it would cost a few hundred to get a spray painter to do it....I would weigh up the cost of a new CPR repro which are available locally.