My friend David writes:
It's now beyond doubt that limited atonement was never a core doctrine of Reformation. Nor was it an essential doctrine of the Reformation. Indeed, it was not even a doctrine of the Reformation. The only candidates we have could be Bucer and Knox. For Knox there is no affirmation or assertion for limited atonement in his works that I know of; for sure, no express denial of it either. For Bucer, some secondary sources argue that he held to it, but I have seen statements which indicate he took the standard Augustinian line.

So apart from these two possible candidates for limited atonement, its not present in all the original Reformers.

Its just not there.

We welcome any responses that can show otherwise.