Someone here may have mentioned the issue of TC-zeners already, but if not, you should be aware of the details. Is this zener spot used as the reference for the whole power supply, or is it elsewhere in the circuit? Do you have the Tek part number? If it's the reference, then you should use the Tek part number equivalent, which can be found easily.
With TC-zeners, they may on the surface look regular spec-wise, but the tempco spec is much tighter, compared to normal zeners.
Ed
