Hi Kaha,
[...]purchased an H3DII-39 from the LuLa forum (private sale) does this still qualify for the upgrade program to an H4D-50?
Yes. Upgrade/Trade-in program is for the Hasselblad owner; possess the equipment = you are eligible.
[...]purchased from the same country of origin to qualify for the 'Customer Care Program', warranty service, upgrades etc?
Customer Care and Warranty are country-specific; the delay in customs is significant and in some countries - prone to loss or high tariff. You are supporting your regional area when using the service center (meaning - with your support, the service center exists), and Hasselblad makes that part of the service warranty - buy in the US = service in the US. The alternative is waiting longer periods for any service work; not a popular option as you can imagine.
The new camera (as a result of your trade-in or upgrade) is
under the same rule as selling a new camera and therefore local dealers sell it locally, not globally. Following this, one could buy a used camera anywhere (please be a smart buyer...scams are abound) and then locally upgrade/trade-in.
If it is to good to be true, it probably is - caveat emptor!So if I buy the camera from overseas does this revoke any future H4D upgrade option with my local dealer?
No. A provocative question: does your local dealer provide value in the form of camera advice, or shooting technique - perhaps workflow ideas - that have helped you in your craft? Enabled you to perform your photographic role more competitively in a creative way or business function? If there is value, you support that value source by investing with your local dealer.
Knowledge has a cost.
Of course, if there is no value, then the argument is invalid.
John