Predator Backpack and Cannon - Need help finding model parts.

[Art Andrews]

Here is another piece I am trying to find and it is REALLY tough because 2/3 of the part has broken off the original model.

This piece is strikingly similar to the road wheel from a Tamiya 1:35 M10 Tank Destoyer... but I don't think it is an exact match. As with the other pieces, any help would be appreciated.