It is a little bit hard to tell what brand it is from the pictures posted so far. Maybe some from further back would help. My guess is that it is not a Zip-Dee or an A&E, so perhaps it is a Carefree, or maybe the lower mounting brackets are some kind of kludge created by the PO.
Typically the Carefree/A&E awnings are mounted with some long lag bolts. They usually try to make the lower mounting point go right through the belt line because the C-channel is behind that. That is not only as solid a place as you will find on the trailer, there is also more metal there than just about anywhere. Your front lower mount may be just a matter of the screws getting loose or maybe they have wallered out the holes and need to be replaced with something bigger. The rear lower mount is, without a doubt, too low. Not only is there no rib or channel behind where it is mounted, but it is bolted into a portion of the bellywrap that is only fastened to the main shell with a few pop rivets under the beltline trim.
The mounting of awnings on some of these vintage trailers is always interesting/creative. My trailer had the rear lower mount right in the middle of the battery access door, so that you had to disconnect the awning arm before you could open the door. What a mess.