If you stole the lockpicks early and then accepted the quest to steal them, they were put back where you got them, and you can simply go back to the town watch building and steal them again.
If you dropped the lockpick directly on the ground they may have disappeared (though I don't know why you would want to drop them). In that case you can replace them: see
Lost Items - guide and directory of inventory files.
Some of the changes and fixes in the original download version of the game were inadvertently lost when the game was patched (to fix a serious new bug), including some of the fixes in some disk version patches. Generally these are minor issues, though, with fixes or workarounds if they are encountered.
FWIW I played half my first game in the unpatched disk version without running into any serious problems. The only reason I installed the hotfix was because the magic lockpicks broke, which is fixed in the download version.
