The Michelin Defender tires were six years old, and had some visible cracking in two of the sidewalls. The tread, however, was supple and deep. Ok to run around locally, but not suitable for a trip of any length. Since I had the 16 inch wheels on the bus, there are a decent number of options, including a new set of the Michelins which are quiet and comfortable.
One well-regarded option was the General Grabber AT2. It is a stable in the Vanagon community for Synchros. For 2WD Vanagons, it helps you get to places off the beaten path, but below 4WD territory. Perfect for getting to all but the most remote campsites. It also has a 50,000 mile treadlife warranty, and is reportedly not that noisy. All this, with a beefy good looking tread, and they are relatively affordable. Any tire with 1300 reviews and a 4,5 rating on Tire Rack is a good bet. Sold.