You can go a long way with just a mobile phone , credit card and passport!
However to try and be a tad more helpful:
1 Spares are generally useless as Sod's law dictate that the one you actually need is the one you left in your garage. I would perhaps take a few relays, fuses, some electrical tape, gaffer tape, and a few choice hand tools.
2 Try to pack reasonably light , two bags behind the seats , and one larger one on the rack have seem to do us many a week abroad. Just be prepared to do some laundry at staging stops.
3 Try not to have a rigid schedule, and just go with the flow, you can book accommodation pretty much anywhere with a mobile (and a reasonable signal) almost everywhere now, and most decent Apps will show you the location of nearby hotels. Plan a few "key" stops perhaps and make a couple of advanced reservations if in a very touristy area, but we have always found somewhere without paying the earth, just try to relax even if it gets quite late.
Unless you are desperate to get through an area quickly don't be tempted to run more than 300 miles a day. It is much more pleasant to do 2 hour stretches between coffee stops and amble along taking lots of photos and being prepared to be diverted to explore castles, palaces, towns, museums or whatever you particular interest might be.
4 Try to read up as much as possible in advance and don't get bogged down with taking multiple guide books. Likewise paper maps take up a lot of space in the cabin, but a few key ones may save you time when the SatNav slingshots you into a traffic jam from hell. The only issue is which ones do you take!
5 I don't take spare water or oil, but others feel these are essential, but I do check the car over pretty carefully each morning before setting off.
Touring in the Morgan is a very special experience , enjoy it to the full.
