I regards to the H objects I was unable to track down I've recently been informed (thanks John Bambury) that these are Harvard Objects:
http://home.comcast.net/~lsmch/cluster-harvard-info.htm
Initially I thought I was searching for the wrong designator but it seems this varies slightly. In the current Uranometria they are designated Ha and in Stellarium (desktop version) they are found by searching the full name Harvard. The coordinates are very slightly askew if you look at the Astronomy League Southern Sky Binocular list but they are close enough to find what you're looking for. Some of these objects also have a Collinder designation.
Harvard 5 (Crux) = Collinder 258
Harvard 6 (Musca) = Collinder 261
Harvard 10 (Norma) = Collinder 299
Harvard 13 (Ara) = No other name
While I'm sure these objects are well known to many more experienced than I, I did find it challenging at first to get information on them. A big reason I couldn't find them on the night I was out observing was that I only had my smartphone planetarium apps available and none of these show the H objects with any kind of designator (Redshift, Stellarium mobile, Star Walk 2, Sky Safari 4).
Again thanks to John Bambury for providing all the information.