Thanks OT,
I downloaded the ArialMT from Free fonts, but unfortunately it didn't include the Arial-BoldMT.
I've done some poking around and it looks to me like the "ArialMT" font "suitcase" was a PostScript Type 1 font that came included in Adobe Reader 5.0. I'm pretty sure Adobe Reader 5.0 was installed on my computer when I bought it back in 2004. The suitcase included regular, italic, bold, bold italic, etc. The files are still on my computer - including one called ArialBolMT but it won't install. I believe I'm missing a piece of the font "suitcase" that needs to be present in order for the font to function.
To anyone else, I could suggest looking in:
HD>System Folder>Application Support>Adobe>PDFL>5.0>Fonts>
ArialMT
ArialBolItaMT
ArialBolMT
ArialItalMT
It's worth a try to double click the above files and see if the Arial-BoldMT will install.
Anyway, since I don't have an Adobe Reader 5.0 disc, I'm going to try your suggestion and put in the original system install disc and see if Adobe Reader 5.0 is on there, extract it and see if I can get the whole font suitcase again, AND get it to work with Leopard.
Thanks again OT!