Freewheeler Passenger Footboard Fixing Bolt Size

[lingone]

Can anyone tell me the size of the bolts that fix the passenger footboards to the frame? (I am away from my trike at the moment, so cannot check for myself).
I am guessing from memory that they are 3/8" with 12 threads per inch (TPI), but if someone could confirm the bolt diameter and thread I would be most grateful.

 

[N8DC]

If they are 3/8 they would be 16 tpi . I can look later today .