While the sources are weak (I can't locate my copy of Cardew or Willoughby, they are somewhere in the stacks, but then neither is usefully indexed), Hodson's had a very nasty time of it in Iraq (much of it sounding pretty modern). Their most famous action was their famous defence of the armoured train at Samawa, 3 September 1920. As yet, we have no really serious treatment of the post-armistace actions in Iraq, though I know of several scholars who are working on this (met several of them in the National Archives in Delhi). Sources to start with now (beyond the regimental histories alluded to above): Haldane's self-serving The Insurrection in Mesopotamia 1920 (interesting title?), Jackson's always-valuable India's Army, and the sacred text Gaylor's Sons of John Company.