I know Koyker made the loader for the 5740 (at one time anyway), not sure if they made others. I don't have any labels on my loader either. Is your the curved arm style or the welded-angular type? If you need pics of it let me know, I can give you closeups of mine.
Thanks for the replies! The parts guy at Montana has been real helpful. He faxed me a copy of the installation and parts manual on my loader this morning and told me it was an Amerequip.