Excellent site Henk, thanks.
On a side note. My strat has a few small nicks in the lacquer at the neck joint and the side. The colour would appear to be reddish, much more like the pic of alder than the basswood one from that site.
I'm tempted to try and take the neck off just to find out now :D
The nicks are not a good indication of the actual wood color, you need to check on a bare/untreated patch which usually is much lighter.
If you do take off the neck make a mental not of how tight the screws are and if you put it back line it up well, pushing it gently towards the body for maximum contact. I left both E strings on the body to get the neck exactly right.
The smarter thing to do is to call the tech who set it up for you, he might remember what bodywood it was, at least worth a try IMO.
If you are going to take it off, make a pic if you can, with the neck as a reference if possible, like this pic of my JV.

Note that the wood patch is a bit pale due to the flash, so the pinkish tone is a bit more red in reality.

The color of the wood where the paint chipped off is much darker and some of the pigmentation of the 3 tone sunburst is in there.
I just love that vintage-y JV feel!!!!!!!!!!!!!