Looks like you don't have a picture of an Imperial Siege Tower, so here you go.
When I got these towers, they had already been taken out of their boxes. Most of the towers had the wheels included in the picture of the tower I've attached. But there was 1 different set of wheels shown at the left of the 2nd picture.
The different kind of wheels don't fit the towers exacly, so I assume they're replacements for the original set of wheels that were probably lost. But with a bit of shaving & fiddling, these wheels could be made to work.
