Does he have any other characteristics, apart from Jewishness?
Srsly though I have lots of elderly Jewish relatives and I gots the hookup.
Ten Commandments Sticky Notes
Money Clip that says "Gelt"
It also sort of makes a big difference, if being Jewish IS his main characteristic, whether we're talking Orthodox or Reform or what because it makes a big difference in how seriously he takes things.
Tzedakah (charity) boxes, Mezuzahs, donations to Chabad.org and stuff like that are all good for a classier gift or someone who wants to take themselves seriously.
If not, there are tons of places online that sell matzo-patterned LET MY PEOPLE GO toilet seat covers.