DUAL HOOK MORTISE LOCK

I need a dual hook lock but no picture original lock has been removed already and disposed of regretfully. I do have the door model number if that would help. What else would I need to help identify the lock? I have order two lucks without good results.
The info pulled from the door:
MI Windows & Door 16457042.15 570FRAME
Series 570 SGD
AAMA/NWWDA 1011S 2-97

SGD-R15-144x95
SGD-R20-144x96 (MODIF)

I understand that this may reference the door only but hopefully may indicate type of locking mechanism also but can NOT find a match anywhere.

Thank you for ANY input that may solve my problem.