Ok mechanical skill is not an issue so with the question being an interstate with 90k and a tour trike with with 30k what way would you go to end up with an IS trike
Nothing changes. Since a lot of GL1500 have excessive miles over the 100K, all else being equal, I would rather have the bike that has been used.
Like mentioned, you should be able to get some reasonable amount of coins for the T.
If you are looking at other things, it makes good sense that once you trike out your bike, quitting riding will come soon enough. Buy a bike that already is triked, even a GW.