TOPIC:

I would like to setup the rig properly on my new to me Albacore. In order to measure rake according to the guides I've found on the internet you need to use the lower point height as a reference. Now I don't have any bands on the mast, so I'm presuming the lower point height is where the top of the boom intersects that mast when at 90 degrees (interesting the class rules don't seem to make any reference to boom position).

The guides are all a bit ambiguous on the next stage. What I think they are saying is attach your tape measure to the halyard so that the lower point height is at 5640mm, then lock the halyard in that position for the rake measurements.

Is that correct?

There is a 100mm tolerance on the boom height which may be the reason for the ambiguity. Most boats these days are rigged with the boom as high as allowed and the tuning guides reflect this.
I would recommend you get your black bands sorted first as if you have a lower boom all the measurements will be out.
The datum point is the sheer line, if you are lucky you will have this marked (scored) on your mast - but do check it is in the right place. Once you have that sorted the rest is simple measurement.

John