I'm looking to install my own fuse panel. Can you tell me where they mounted your panel? Maybe some pictures. Also have you been able to determine what any of the other connectors are for?
I know this thread is old, but better late than never. Item D above is a connector for Kubota hazard or work light switches. An example of the work light switch would be R240153242 for a Kubota excavator. I know you only asked about what it was for, but people have asked about these connectors in other posts. The connector is a Sumatomi nonsealed MT series 6242-5061. Sumatomi catalog is here 自動車用部品:Sumitomo Wiring Systems, Ltd. You can buy the connector at Eastern Beaver. It is listed as the 6P090-MT SPA Female for $2.03.