Depends upon the particular maker and time period
For the "classic" Lehigh wrist (like Hermann Rupp, for example) the wrist is very narrow vertically, with the narrowest portion near the rear curl of the triggerguard. You may even do the "dished up" shape, where the bottom line of the stock rises a bit right at the trigger to make the wrist even narrower. The top of the wrist should be durn near straight, with very little curvature and very little drop.
Other Lehigh makers did things differently.