Polytonic Greek pneuma letters (spirits) and half-eta glyphs

[Philippe Verdy]

This page on the French version of wikipedia notes that Polytonic Greek used 
in the 3rd century B.C. alternate letters to denote the initial spirits 
("pneuma das�" for the "hard" spirit, and "pneuma ps�lon" for the "soft" 
spirit), rather than the modern 9-shaped combining accents.

http://fr.wikipedia.org/wiki/Diacritiques_de_l%27alphabet_grec
(Note: to see all letters in Internet Explorer, you have to configure it to 
use the "Arial Unicode MS" font from Office or the free "Code2000" font, and 
to indicate to Internet Explorer, in the Accessibility options, to ignore 
the fonts styles selected on web pages: the default font selected in the 
Wikipedia CSS stylesheet for Internet Explorer forces the "Arial" font which 
does not contain glyphs for all these characters; apparently Wikipedia has 
problems to find a reliable way to configure their stylesheets to work with 
various versions of Windows or IE).

These letters were noted initially by Aristophane with a variant of the 
historic "H" letter that noted the /h/ sound (but was later borrowed when it 
became unused to note the sound /�/ with eta), by cutting the "H" (eta) 
glyph in two half-parts (and sometimes found with L-shaped glyphs without 
the lower part of the vertical). These historic phonemes subsist today only 
as diacritics for modern polytonic greek, but this is not the case of 
historic texts where they may still be pronounced /h/ on initial vowels or 
diphtongues or rho.

The same page gives an encoding for the latest non-combining form where 
these spirits are represented by upper tacks (before they became 
diacritics). My question is: can these historic half-eta letters be unified 
with these tacks, or are they distinct letters?

Are there variants encoded for these historic half-eta letters, to mean that 
they should not be shown with the upper tack glyphs but with the historic 
half-eta glyphs?