Manually moving config from vCenter Windows 6 to vCSA 6.5

Hi,

we would like to move a small (essentials) dev network from 6.0 vCenter Windows to the new 6.5 vCenter Appliance.

Unfortunately, the automatic migration does not work because of  FATAL error "vmonapi"  while migrating from Windows 6.0 to Appliance 6.5

So, our idea was to setup a new 6.5 appliance and move some config manually as we only need the three 'essentials' host and we do not need any records or older logs.

Any tips what would be the best way to do such a thing?

Whch files or config to bring over?

Anyone did this before? At which point do we need to shut down the old vCenter Windows server in this manual process?

Thanks for any comments

PS: Reason for doing it this way is because we are not expecting any help solving  FATAL error "vmonapi" while migrating from Windows 6.0 to Appliance 6.5 without a commercial support ticket.