Sorted it - after much wailing and nashing of teeth:
Select IF Type is equal to "Text"
el = activeDoc.firstSelectedElement
WHILE (Exists (el) = true)
a = el.box.top - el.box.bottom
IF (a < 6 - true) THEN
el.fill = color_black
END IF
el = el.nextSelectedElement
END WHILE
Select none
This routine fills the smaller text with a predefined colour (color_black) which I can then use as a selection criteria in future comands.
Thanks for your keen interest Trevor