I fitted an acrylic glass to a 1950's pocket watch about a year ago and it's fine, I used Araldite precision, I first took off the bezel from the watch case and cleaned it in cleaner, then I applied a thin bead of the cement to each surface with a fine needle while using an eyeglass, fitting the glass and leaving it slightly weighted for 24 hours to set. The cement formed a good bond and is invisible to the naked eye and only just visible through an eyeglass, hope this helps.