Did the same thing a few months ago and replaced the screen/digitizer via an e-Bay seller, gadgetfix - $40-ish. First one didn't work (screen freeze, buttons unresponsive). Returned and quickly received a replacement that worked fine, the screen was beautiful again (thanks, LE55ONS on youtube). Then, last week, dropped the phone again. This time the screen survived but chipped the case on the corners and cracked it near the sim card slot. Back to e-Bay again, this time for a new case, $20. Just installed that this morning (thanks, Bud Maloney, youtube) and now I have a nearly new L920: great screen and a glossy red back - no blemishes on either. My L920 just keeps humming, all hail the L920.
The screen repair was a little involved the first time but easy after that. The back cover replacement was simple. I replaced my red back cover with another red cover but am thinking I might mix it up a bit with a white or cyan one. I'll keep the 2-year+ old L920 until I can get my hands on a 640XL, then go with the Win10 flagship when that launches.
Edit: I've also replaced the battery, so no more complaints there. About the quality of the parts: both the replacement screen/digitizer and back appeared to be genuine OEM parts. The screen had the Nokia brand on it and the back cover was absolutely identical to the part it replaced. Recommend both e-Bay sellers mentioned based on my experience.