What is this?

[rjohnstone]

What is a 'screened logo'? Do you mean that it's not finished with clear paint but with some sort of plastic? Right at the tip of the headstock this plastic seems to have come off and was fixed again. What would it mean for the guitar if it were screened? Is it a fake?

No, it's legit. From the pic you originally posted, it looked like the Ontario silk screened logo. My eyes suck and the pic was pretty small. The early logos were water slide decals.
And yes, they are on a plastic (Phenolic) cap.
I see in the closeup that yours has the TM instead of the R, so that would make it an SD era neck.
Jackson typically put the "MADE IN USA" UNDER the Jackson logo on SD guitars, but as I stated earlier, they did also stick anywhere they could or sometimes left it off all together.
You'll notice on some of the previous pics that the logo placement is a bit sloppy or portions were shaved off during finishing. That was typical of the logos that were decals.

[straycat]

My strat head in the gallery 5490(86) has the made in USA after the logo as well.It is a decal not screened bucause the headstock was not painted.
Looks legit to me.

[j2379]

ive got 3 86 jackson bolton necks here. a 7/86, 10/86 & i tihnk 9/86. & they all have a different logo. 2 TM logo's usa after & under, one R usa after.

[StefanEndres]

Thank you guys for helping me with your deep knowledge. I've finally bought the guitar for 400 Euro (about 600 $). I think that's ok because the EMG pickups alone cost about 300 Euro, and it's in pretty good condition. Does anyone know how much this guitar cost back in the 80s?

[Axewielder]

I would say $600 was a great price, especially for outside the US.

[dg]

Nicely done, Stefan! Enjoy!

As to price, the '84 Charvel pricelist had Solid Color, HSS, Kahler at $1270 (that's $2610 in 2008 dollars, btw). Probably would have been a little more in '86. Not sure what discount was available through dealers back then.

http://audiozone.dk/cm/displayimage.php?pid=427&fullsize=1