as the topic asks.. how do you lock the decklid? or can't you?
should be the same. You might need to bend the tab on the body down/out a bit to compenate for the different angle of the hood
i have bent the tab, so the latch catches.. but i can only turn the key half way around??.. when i turned the key, with the lid up.. i couldnt see
anything move.. so i dont understand why i cant lock it 
Nope thats part of the deal with the stand offs.
There Must be a way....
I have tried to look at engines with standoffs and couldn't open them...
You must have to bend the locking tab on the body a fair bit, as the engine lid is locked when its completely closed ....
open the top a few inches... must make a difference...
Or Maybe file a larger groove in the latch itself.....
Nothing is impossible... just a bit harder....
Lee
my beetle used to lock, now i just gota tighten the standoffs properly, bend the tab on the hood a bit and should work 
as my deck lid has a two position hinge and if its in the open position I made a latch with a second hook about 15 mm longer to lock in the out or normal position work great.
On a 68-on car, carefully bend out the tab/catch on the body approx 10mm so that the hook on the latch can 'click' over it (when the lid is out)