Is #14-24 correct?
At the risk of being accused of heresy - I just purchased and installed 4 metric hex socket head machine screws. Sized 6 mm by 1.0 and 12 mm (long). Reid (RIP) suggested them years ago as an easy to install screw that was just the right size and pitch to have a friction fit without messing up the threads. Why did I do this now? Because I just had a puddle under my speedster when I brought it into the garage the other day. Upon checking, I found 3 of the 4 screws slightly loose and the 4th gone! Even after using lock wase=hers and Ultra Black RTV. For over 30 years I've used the regular Ford style screws and had them loosen up on me on occasion causing leaks. This time it could easily have cost me a babbitt job if the screw came out on tour. My cars won't be using the stock screws again. Oh, the long allen wrench makes these a piece of cake to install too.
Steve ,I converted over to the hex machine screws also, Don't remember the size but our last rebuilder retapped the hole for modern thread size . Getting that inner slotted screw in and tight is a battle. I have a dedicated socket Allen wrench for the job.
They are available from Langs @ $1.50 per set and have the correct heads too.
Ford used lock washers under the heads of the Bendix cover screws. If the hogshead hole threads are still good (not messed with by use of some other screw thread) then the Bendix screws will stay put. But you should always check over important nuts, bolts, and screws on the Model T during service checks.
Like to use very small washers and then small lock washers for open slot type covers too.