Good info -
Does he like souvenier type stuff? There's one pack of presidential m&ms on ebay atm. They're a famous thing (like people who go to the WH for whatever try to snag a box), they're at the White House or on Air Force One, little boxes of m&ms with the Presidential Seal and a (printed) signature of whatever president is in office at the time.
Here's a link to the listing.
Also on ebay other interesting little things that people into politics and presidential things might like like
this listing for a backstage pass from the last DNC convention. There are passes from other conventions of both parties available - I just picked the top listing for convention pass.
Also places you can buy campaign posters, pins, etc., from past elections.
This book of presidential campaign poster art comes out in May. I think the trip to the historical site is a great idea, just adding in stuff goes with that can be had for reasonable.
I dunno what you want to spend but you can get a signed Ian Fleming for a couple hundred bucks from a number of sources. First editions are a couple of grand. You could do like, the entire set of Bond books or movies or whatnot.
Again if he likes interesting collectible little things or desk stuff, if you search 'James Bond prop' on ebay, you'll find a wealth of things from replica Bond rings and gadgets to things used in the actual movies (lot of poker chips, heh), to etc. Also a number of versions of Bond's watches available from different films, ranging in price from a couple hundred to a $25k Rolex.
Anything?