I have always found the Druz fastenings on the cowl frustrating. Three would line up and the fourth - only after a struggle. As a result of this perverse behaviour, I have been reluctant to take the cowl on and off and use the storage space beneath. Proper' old fashioned catches are now an option for new builds, but these are also easily sourced from various suppliers. I acquired some from Vantage Car Parts.
https://www.vintagecarparts.co.uk/products/148-bonnet-catch-small-chromeI had wondered about how best to fix them and then read Peter Beasley's excellent blog. He used double sided adhesive tape to stabilise the fixtures whilst drilling. So below are some 'show and tell' pictures of how I did it for the back pair.

The two components had 3M Extreme Mounting Tape attached to the fit surface. This was cut around the base with a very sharp scalpel and also around the holes, as seen, to avoid the drill picking up the tape.

The latching component was positioned 10" from the back corner, with the rubber bumper resting against the cowl. Pressing down on the latch base makes the double sided adhesive pad grip the bodywork and stabilises the component for nice and safe drilling.

The cowl was removed, the clip folded back on itself and then the bodywork drilled 2.9mm, the tapping size for the M3.5 dome head socket bolts I was using.

The aluminium body was tapped for the bolt size, as was the ash beneath to a limited extent. The fixture was then bolted down through this hole and the second hole then drilled, tapped and held down with another 20 mm long, M3.5 bolt. The bolts were effectively self tapping in the wood for the last 1/4", a technique developed by Peter in his blog.
The top pin was located 3.75" (at the bottom edge) above the base of the cowl and held in place with the double sided adhesive pad. Two, 3.5 mm diameter, clearance holes were made using the fixture to act as drill guide through the cowl


Rather than using separate nuts and washers, I thought it neater, and certainly stronger, to make up a brass bolting plate. This was obviously made to match the fixture and the screws were loctited in place. Quite unlikely to shake loose.

Just took a garage snap of the latch fixing in place. I will need to make up a blanking plug for the rear Druz holes: either some black delrin or a bit of polished stainless.
The front latches will be easy to fit. There is the triangular access hole under the cowl for the pedal box(es), L & R, that will allow the latch fixings to be accessed underneath the bodywork, which is only thin aluminium in this region. This will definitely use a screw plate to distribute the load from the pull of the latch and also be far less fiddly than separate nuts and washers.
I won't have time before the Albert Ball run next weekend to fit the front latches, so the front Druz fastenings will stay for the time being. Indeed, in conversation with Mark H, he suggested that a pair do give better stability and security to the cowl than the latches. The alternative would of course be to have a properly functional leather strap. All this may be teaching grandmother to suck eggs, but someone might find it useful.
Tim