Hi Paddy & All,
Well the short answer to your question is that I conversed with David Frew over this very topic about 12-15 years ago and he set me straight on it (David was then studying to become a professional astronomer) and gave me a list.
Interestingly as a result of your question, I opened Megastar (V5) tonight to track down the purported G.Cs and found a lot of them have "disappeared". In the older versions of Megastar there were heaps. They are now fewer. One example is NGC 1978. In v3 and 4 (I think) it is marked as a G.C. in v5 is is marked as an O.C.
In fact the ages of so much of the stuff in the LMC and SMC is not particularly well known. I've read a lot of journal reports tonight to discover the state of things and they are now more mixed than they were 15 years ago.
Back then, professionals had a pretty rigid definition of what a G.C was -- ie Population II stars, extreme age, metal poor, horizontal branch etc. But many of the more recent papers I've read tonight seem to be content to call many of these clusters "globular" while at the same time commenting on their relatively young ages 1-3 gyr, lack of RR Lyrae stars and horizontal branch. Some other papers refer to them as "intermediate age" clusters and comment that these LMC objects (in particular the LMC) are in effect a snapshot of what our Milky Way G.C's looked like 6-10 gyr ago.
So it seems the water has been "muddied" from what I believed.
You might find some interesting reading here:
http://nedwww.ipac.caltech.edu/level..._contents.html
This may be interesting too:
http://www.univie.ac.at/webda/smc_cat.html
The oldest cluster in the SMC is NGC 121 just over 10gyr old and has several RR Lyrae variable stars. Kron 3 is the second (measured) oldest about 9.7gyr and has none. Curious ...
if I think of it, I'll keep digging. One thing I have found with some certainty -- NGC 2257 is a classical G.C. NGC 1978 is a young intermediate age cluster and not comparable with a "true" G.C.
Still reading ...
Hector (Andrew Murrell) may well know a quicker and better answer than I ...
Best,
Les D