Rest assured that trying to turn the pump with the belts on was only a quick shadetree check of the pump. The belts will be coming off for a more thourough check. I don't think the squeal was due to loose belts, they have about 3/8 inch deflection, max.
As soon as I got in from work today I went straight to the garage and checked the fluid (steering fluid, not ATF). The car had been sitting for almost 24 hours, and the fluid appeared to be slightly pink. Looked like the color was due to air bubbles, which were still suspended in the fluid. I find no leaks or drips coming from the pressure or return line. Not sure where air would be getting in the system.
When I pull the belts and check the pump closer, I'll pass on my findings.
73 280 SEL 4.5