King Irv and the Holy Grail

King Irv, Jewish ruler of the Wholesale Kingdom, has a time travel machine invented by his clever Merlin, Hershel. The Christian kings of old England are readying crusades to retrieve something they call the Holy Grail, the cup they believed their savoir drank from at the Last Supper, from the heathens of the Middle East. At the urging of King Arthur, a Druid from the west of the British Isles, King Irv's Merlin decides he can go back in time and procure this Holy Grail thing from right under the nose of the Christian savior. Kings Irv and Arthur can then sell it to the highest bidder. Snatching the grail cup is an easy task, but proving its authenticity to the Christian kings of old blighty proves to be more of a challenge. King Irv's son-in-law in future England, around 2002, has better luck with the sacred cup, up to a point, but before all the bets are in, this sought-after Christian relic comes close to launching a holy war across both time and space.