This is mainly an FYI for any other older Endeavor owners. Mine is a '97 and during the winter, one of the two engine door latches broke. It looks like a plastic knob that you grasp between your fore finger and thumb, and turn. It is basically a large "thumb latch", but much larger diameter than the ones sold through the camping stores. The plastic part just broke off.
You wouldn't think this would be hard to identify or replace, but like many things (especially on an older unit) they had a heck of a time identifying the right part. After two wrong latches (from Monaco Parts) they finally figured out the correct one. The part is manufactured by Southco and is Southco part number E3-10-505-50. The HR part number is 34371. Now that I know the Southco part number, I actually found it on Ebay as well (wasn't any cheaper than Monaco though). Hopefully this will help someone in the future.