Thanks for that info John! I Did not know that. I considered putting a rabbet onto the bottom of the support but decided to flush mount it.
In fact, since we have never used our sink or taps I have removed all of them and I am making up a wooden counter top for the base cabinet. I will flush mount both the left side and right side supports to the new counter top. I don't want to add a whole lot of weight
but I would like to make a nice study support and cabinet set up.
I sure appreciate the insight.