New op amps, good idea?

I have recently acquired an old crossover which was highly rated in its day (early 1990's). I know technology has improved dramatically since then in many regards but assuming I want to keep and potentially improve this particular one rather than buy a newer version of it (not available), is it worth sending it to a trusted local electronics shop who specializes in such things and asking him to upgrade the op amps with newer/faster/better...? I realize I am not helping its resale and will probably hurt it but if that's not a big concern... I've been told it was a great unit in its day but that it may be considered less transparent than today's similar offerings...
My technician assured me it was not going to be a lot of money (perhaps $100-$200 or so ) and that he was quite confident he could make a noticeable improvement in its performance...If I decide to let him take it what should I be knowledgeable about in order to speak with him intelligently about the work?? Would there be any other mods he could do "while he's at it" that would be reasonably cost effective and sonically helpful as well? Any input would be appreciated as my technical knowledge in all this is limited.... Thanks in advance for any and all opinions. Regards,