I seem to have stumbled and staggered my way to a solution using this
bit of code

Dim Item As Worksheet

For Each Item In ActiveWorkbook.Sheets
Item.Select
ActiveSheet.UsedRange.Select
Selection.Copy
Sheets("Master").[A65536].End(xlUp)(2).PasteSpecial
Paste:=xlValues

Next Item

I'll carry on testing and come back here if I run into snags.
Meanwhile if any of you see any potential disasters that might occur
do give a shout, I don't have much of a clue with any of this!

If it continues to work I'll be back with another query because I have
next to work on the block of data  that I get from this stage of the
processing.