No, don't try to use MapSouce like that as I just replied to you in the MS thread. For BlueCharts which are supplied only in a .img file it's simply not possible to 'install' them to a computor in any meaningful way. Only very old BlueCharts are supplied in a form to be installed for MS.
You should place the chart on a microSD card: Garmin/gmapsupp.img works with all devices. If your maps aren't 'unofficial' (purchased for media card or device) then you must unlock them correctly. Search for gimunlock.
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