Achromatic lens cement

Hi All, I am renovating a wide angle eyepiece system and found that
the cement between one of the achromats had developed many bubbles. I
soaked the lens in acetone for a couple of days and succeeded in
dissolving the old cement. Could anyone tell me what kind of cement to
use to re-attach the two components. I have some Canada Balsam which
is fairly old (about 35 years) but think that there must be something
better to use by now.
Thanks Brian Morse Vancouver.