Watch List notes:

James II (1685-88), Shilling, 1686, laureate and draped bust left, rev. e over t in et, crowned shields cruciform (ESC 764 [-] [R2]; S.3410), toned, with some weakness to French shield, otherwise very fine, very rare.
Provenance:
Spink auction 215, 4 December 2012, lot 293

One is inclined to believe the rarity is greater that R2, for this error had not been documented prior to auction in 2012, and no further examples have become known to the cataloguer since.
Estimate: £800 - £1,000