I keep coming across my stuff by Spurgeon that makes me think he was a closet post-mil. Commenting on on the Holy Spirit's chief work in History he says:
The eternal purpose of God to set his king upon the throne, and to make Jesus Christ reign for ever and ever, must be fulfilled, for the Holy Ghost has undertaken to see it accomplished. Amidst the surging tumult of the battle, the result of the conflict is never in doubt for a moment. It may seem as though the fate of Christ’s cause hung in a balance, and that the scales were in equilibrium; but it is not so. The glory of Christ never wanes; it must increase from day to day; and the day shall come when Christ’s praise shall go up from all human tongues.
That sounds like the 8 cylinder, turbo-charged version of postmillenialism to me - way to go Spurgeon!