There has never been any putter specs in the game as far as I'm aware. I suspect if you check through your other clubs you'll find that what you thought was a legendary putter spec was actually something else... Possibly a ball spec if it wasn't for one of the other club types.
There has never been any spec for putter as far as I know. The only way to get spec is to buy them in the store. I have played this game everyday since the beginning. Every day I have looked in the store for spec, never seen any for putter. The only thing I saw were new putter, grip and shaft. If some ended up with spec on their putter, that's another bug in the game.
