The Mechanic doing the IFR recert would not certify it for IFR. My friend at an aero club had an overhauled one from former 152s that are no more and gave me the overhauled one at no charge. Being the plane is used for IFR training I want the best instruments in the plane. Old one may need more than just an adjustment.
I don't know where your mechanic is getting this from. We've always used +/- 75 feet as the cutoff between airworthy or not (ref. AIM 7-2-3). How long ago was the 91.411 inspection done? What was the error listed compared to the reference altimeter? I still say a 60 foot difference from field elevation is certainly acceptable for VFR and legal for IFR but if you wanted it adjusted, it would be legal for an A&P to adjust it (this is not the same as calibrating it which only an instrument repairman or station could legally do). It's your money and if you want to buy a new instrument knock yourself out.
PS. Or was your "mechanic" an avionics tech doing the 91.411/Part 43 Appendix E check and he couldn't calibrate the altimeter to within tolerance? If that's the case I suspect the plumbing might be a likely suspect which would require a leak test to confirm. I don't like replacing instruments unless the instrument is truly defective.
