I've made some of my signature cork&volcanic sand bases for these old grey knights. They were some of the first 40k minis I painted (my eyes!), instead of repainting them I just added some highlights, did the shields and the parchements. The bases were god awful so they were in need of a full remake; that way they also fit with the rest of my marine/custodes collection.
Funnily enough these are some (the only?) of the models that costed more back in the day (50eur) than nowadays (35). Since GW separated all the inquisitoriall sutff from GK in order to sell twice the codexs and earn twice the money I'm thinking into getting a box of the newer plastics to get a more rounded up army (and some nice ingame benefits).
Don't look into their eyes...
Muh mystical doddle
I've also done these white scars bikes that had been lying in the ole pile o' shame for several years
Chadstodes are better anyway