Synology - Upgrade 1515+ to 1517+
Worked like a charm
https://github.com/prt1999/Synology_model_upgrade
Ran the above process
Forum Discussions
https://xpenology.com/forum/topic/69328-converting-ds1515-into-ds1517-dsm-72/page/3/
https://xpenology.com/forum/topic/69328-converting-ds1515-into-ds1517-dsm-72/