Bruce
TVWBB 2-Star Olympian
Yep, the frames should be the same for the 1000 and 1100. It is common for the frames to be rotted out, especially where the cook box connects to the frame on the left side where the bolt goes through. If that is the only place it is badly rusted, you can replace that bar: https://tvwbb.com/showthread.php?77334-HOW-TO-Weber-Frame-Cross-Member-repair
Otherwise, your best bet is to find a donor grill.
Otherwise, your best bet is to find a donor grill.