Unidentified Hatchment

eBay vendor, the-school-for-scandal, is offering for sale an, as yet, unidentified hatchment. By repute the hatchment was housed in Fawsley Hall Northamptonshire England, an estate owned by the Knightley family.  However, neither Arms seem to relate to Knightley.  The offer price is £2,995.00

Arms: Azure on a fess Gules between three leopards’ faces jessant-de-lys as many mullets of six points Or
impaling
Azure a fess Argent between six crosses crosslet fitchy [couped] Or
Crest: A griffin’s erased head Or
Motto: In Portu Quies

The dexter Arms could be variations of Watkins or Cantelupe and those to sinister could be Haversham.  A quick look through the ten volumes of Hatchments in Britain did not provide any identifications.

Does anyone have any knowledge of these Arms &/or the hatchment?