It is really nice to have two sets of rims/tires that you can swap out for different seasons.
When I used the Defender as a daily driver I used to have MT's on steel rims that I ran from late spring to late fall (off-road season) and had AT's on my stock rims for late fall through the snowy months.
I'd hang on to them. Plus, with all the older discos flooding the market, our rims have dropped so much in value that you really can't expect to get that much for them.
Nice looking Defender by-the-way...soooo you plan on keeping it for a while do you?