Lagu,

In your example:
ID = 7/8”
OD= 1 11/16”
LTH/HT= 1.1/4”

ID is the inside diameter (the hole) of the bush (22.225mm). OT means the outside diameter of the bush (42.8625mm) I’m afraid I have no idea of LHT/HT but the conversion is 31.75mm.

For this bit the conversions are:

The external circle is 16,5 cm (6.49605 inches)
The inner circle is 8,9-9.0 cm (3.50395ins to 3.5433ins)


For the last part
ID is the inside diameter (the hole) of the bush.
OT means the outside diameter of the bush.
A spherical bushing is just what you describe, a ball with a hole in it. It is used because the mountings on either side do not need to be accurately lined up and the axel that runs in them can be slightly bent without problems, The bushes twist in their housings as the cutter rotates to keep the alignment.
Hope that helps,
dAVE.