123,
There were 2 different type Hx mounts (because there were two different transmission bell housings) used on the XP, depending whether it was an early or a late serial number.
Pls confirm - the bracket that is broken - mounts to the VERTICAL face of the transmission bell housing? There a thru bolt on the bracket that screws into the vertical (FLAT) face of the bell housing?
If that’s yours, that is the 2nd type of mount used and that too was changed in later models. Those have two separated brackets, not brazed to the Hx itself. The reason for the change is obvious.
You could buy those brackets and replace just the one side (until the other bracket breaks off, of course.) The Hx body is held to the bracket with a hose clamp. If that’s your type and you need more info - PM me or reply here (but I don’t always monitor this forum.)