Or just sketch what you want and have a metalworker of the period make it. They would have had the precision to manage it particularly if you sacrificed quality and worked in pewter. Pewter is so easy to cast you can pretty much diy.
The Phillips head screwdriver screws are great for not exactly needing the most precise shape for undoing them. Anything sort of in the ball park will work.
Or just sketch what you want and have a metalworker of the period make it. They would have had the precision to manage it particularly if you sacrificed quality and worked in pewter. Pewter is so easy to cast you can pretty much diy.
The Phillips head screwdriver screws are great for not exactly needing the most precise shape for undoing them. Anything sort of in the ball park will work.
Hell, just press a bit of wax into the screw head for an impression, then use lost wax casting to cast a driver.