If you do decide to sell it in pieces rather than a single unit, don't expect much interest in the HO manifold, E7 heads, stock t/b and stock maf
Unless... you find someone with an old XW who wants to convert their car to unleaded the expensive way, or who wants a basic EFI conversion.
You'd be surprised at the interest there is in the 5.0s. Two friends of mine who drive EAs love 5.0s, and would love to do a V8 conversion, but of course much of that is just dreaming. I'm sure there are a few people who have viewed this thread and have gone "damn... a 5.0 in my XF/EA/E-series would be sweet!"
I just hope someone reads it who wants one enough to buy yours