Dear Mahinda,

Thank you very much for your very thorough explanations. We
discussed this half gaathaa with one of my pali teachers.
First of all let me point out all the differences between the CSCD
and Buddhadatta:
1. mahaakaru.naaya / mahaakaru.nayaa
2. paha.taavakaasaava / paha.taavakaasaa
3. dura.mjagaama / duura.m jagaama (please note the short u in the
CSCD)
4. tassa / tassa hi
5. bhavatthu ta.nhaa / vatthuta.nhaa
To summarize, here's the CSCD version :
Citte mahaakaru.naaya paha.taavakaasaava,
Dura.mjagaama viya tassa bhavatthu ta.nhaa.
And here's Buddhadatta's version:
Citte mahaakaru.nayaa paha.taavakaasaa,
Duura.m jagaama viya tassa hi vatthuta.nhaa.
As you have pointed it out, the Buddhadatta version perfectly fits
the Vasantatilakaa meter of a sakkarii paada (14 syllables):
Citte mahaakaru.nayaa paha.taavakaasaa,
LLSLSSSLSSLSLL
Duura.m jagaama viya tassa hi vatthuta.nhaa.
LLSLSSSLSSLSLL

Here's the CSCD version of the full gathaa which indeed doesn't
respect the meter at all, it's the least we can say.
Dehiiti vatthumasuka.m gaditotthikehi,
LLSLSSSLSSLSLS (14 syllables)
Naala.m kathetumha natthi na demicaati;
LLSLLSLSSLSLS (13 syllables)
Citte mahaakaru.naaya paha.taavakaasaava,
LLSLSSLSSSLSLLS (15 syllables)
Dura.mjagaama viya tassa bhavatthu ta.nhaa.
SLSLSSSLSSLSLL (14 syllables)

One could translate the two preceding paadas in the following way:

When asked (gadito) by the needy one (atthikehi) "Give me such a
thing(vatthumasuka.m)"
You should not say "I don't have, I don't give"

Let's continue with : "Citte mahaakaru.nayaa paha.taavakaasaa"
You translated avakaassa by space. According to my teacher it could
also be avakaasa = chance, so this paada could mean "this is a
chance for the great compassion to strike in the mind" or something
like "This is a chance for the great compassion to appear in his
mind." if this makes more sense.
He then translated "duura.m jagaama viya tassa hi vatthuta.nhaa"
by "it is hard for him to overcome the desire for wealth", the idea
being that although great compassion arises in his mind, the desire
for wealth is still strong and might always be an obstacle in giving
to the needy. Here he chose dura.m (difficult) instead of duura.m
(far) and extrapolated jagaama to overcome.

We also had a look at the lines preceding this gaathaa and had quite
some problems with the syntax and spelling. According to my teacher
some of the paa.li is not standard such
as "maatulamahaatherassa.mca" or "saparivaara ve.naa kaani" or
especially "sa"nasaparibhogaarahaani" which he has never heard of
before.

So raajaa mahaa vihaare mahaggha mahaavisaala.m salaakagga.m
kaaraapetvaa anekasahassaana.m bhikkhuuna.m nicca.m salaaka bhatta.m
pa.t.thapesi. Maatulamahaatherassa.mca sakanaama dheyyena mahanta.m
parive.na vihaara.m kaaraapetvaa anekehi kappiyabha.n.dehi saddhi.m
saparivaara ve.naa kaani gaamakkhettaani sa »nasaparibhogaarahaani
katvaa daapesi sattameva nisiithakaale rahogato mahaabodhisattassa
dukkaracaritaani sallakkhento taadisaapadaana.m attani
sampaadetumaasi.msi. Tathaa hi

The meaning could be very approximately:
"Having caused to build a very expensive and very big room for
distributing food by tickets the king always prepares food for many
monks. […] Having gone to a lonely place around midnight, he
remembers the ascetic practices of the Buddha, and wishes to be
endowed with those attributes himself".
avakaasaa= chances (nom. plur.)

So if I understand well, it is the king's greed for wealth which is
referred to. It could either "have gone far away" as you suggest it
or it would also not be completely illogical to think that it
is "hard to overcome", for such a wealthy person.

I understand very well that you are certainly much more familiar
with the Hatthavanagallava.msa than my Pali teacher, but I thought
it could be interesting to mention what he said. By the way, his
name is venerable U Nodhi~naa.na and he teaches at the ITBMU in
Yangon.

Kind regards,

Florent