If you happen to break the fixture, don't panic, new ones are not usually that expensive. Also, if this fixture has had standard incandescent bulbs and has been used a lot, it is very probable that the bulb sockets are burnt. I had to replace one fixture due to this, above the stove, and after that, replaced all the inside bulbs with LED's, which run much cooler. This is one fixture that is available, but there are many that look very similar to the one you have.
https://www.dyersonline.com/arcon-eu...lear-lens.html