You can piecemeal destroyed sections using galvanized pipe or conduit from home depot. Actually shelter logic sells replacements too. Lumber actually works better for the braces, drill and bolt on. The corners look ok and are the special/key part.
It's not a bad idea to run a 2x6 across the peak if this is the smaller 1-1/4 sized frame anyway, support at the ends with one side temporarily removable - helps a lot as far as taking a snow load.
Frame looks pretty salvageable, great opportunity for someone who needs a shelter really. Use the pattern to hack it back together straight, customize a little as works better for you in the process, pull a tarp down tight or shrink wrap and you'd have a good & cheap structure.