There's this Shapeways part created by SteamShield: CW Hot Spot Onslaught Hip Ratchet Stoop Fix (27HCCLJ2F) by SteamShield This item comes in a pair, and you'll have to open the legs and install them as the photos seen on the product page show.
I fixed my onslaughts lean by taking the screws out from each side of the hip, removed the high tension spring(got pegged in the face on the first) and with a dab of super glue(brush kind) coated the pegs for the screws. Seems to be working great so far.