Thanks guys for your attempts to help but I think I have found the answer to the question ... apparently my model is what the moco calls Harley Davidson International and these models are slightly different ..
Here is an extract of from the service manual (yes, I bought a copy in sheer desperation .. hehe)
which I found under the Fork Lock Removal section ..
NOTE
On HDI models, use a center punch to make a pilot hole at the
top of each break-away screw. Install a 1/8 inch left handed
bit in drill and set the drill to reverse. Positioning the bit in the
pilot hole, spin out the break-away screws.
Apparently those two blank screws are what moco calls "breakaway" screws ... some sort of security feature I suppose. Now to get to it and get those heritage bars fitted ...