I'd forget it. Unless you happen to find one on the same exact TV, you're in for a lot of work or $ to get a new correct one. Some are two-piece, and others are one-piece. The outside is a lenticular lens, and the inside is a fresnel diffuser. The fresnel is millions of concentric grooves, which need to be centered. In other words, if you get one too big, you have to cut precise even amounts off all 4 sides. Likelihood of cracking = about 98%
Charles