Front Panel Header Adapter Kit For Dell Optiplex 790 & 990 and Precision T1600 – Harbin Repairs Store
I don't know front panel layout - Dell Community
Front Panel Header Adapter For Dell Optiplex 7010 9010 7020 9020 and Precision T1650 T1700 & 3600 Motherboards – Harbin Repairs Store
Years too late: Everything about Dell front panel connectors from the BTX era that nobody really wanted to know (plus converting an XPS 700 with factory Dell parts). : r/pcmods