Unfortunately, I haven't been able to find biographical information on Lee. But Eric (as he was called and soon used as his signature) is better documented. For starters, you might link here and here.
Lee's style was comparatively solid and literal, whereas Eric soon blossomed into his characteristic sketchy style. Underlying that sketchy style was a solid grasp of the forms he was interpreting. For that reason, I respect him even though the sketchiness usually was too extreme for my taste.