Value of Brand New WX Head Casting?

[urq]

A long time ago I purchased what I was told was the last bare head casting
available for the WX engine.  I was planning to use it to build up a worked
over WX for my urq.  Well, the car's got an MC-2 in it now and I don't see a
WX going back in its place ... no matter how much I dislike the hydraulic
lifters ;-)

So, now I have this casting, brand new, in the box it was in when I bought
it all those years ago.  The part number is 035 103 351BC.  It is actually
slightly different than the WX head in that it has the passages for the air
shrouded injectors.  If you use the WX inserts the passages would be
blocked, so I know it would work for a stock application ... or the air
shroud parts could be added ... which is what I was planning to do.  I don't
see any other differences.  The head doesn't have valves, springs or a cam,
but it has seats, valve guides, cam bearing caps and all studs ... all nice,
shiny and new.

How would someone determine the value of a part like this?  

TIA!
Steve B
San Jose, CA (USA)