Looking for Calibration HP 16340A/Keithley 5156 0.1/1.0 Gig ohms

[Bryan]

I'm looking for someone that can give me some good (17025 accredited) uncertainty at a nominal 100 Meg Ohm & 1 Gig ohm, say 200 & 300 ppm respectively.  I have an old HP 16340A box that seems to be along the lines of the Keithley 5156 "Electrometer Calibration Standard" that I need reported.  These things have a resistor in series with triax connectors on each end, I presume there is some shielding.  I tried to get to Keithley's Primary lab, their scope indicates it's right up their alley but instead got shunted off to some Tektronix service center clearing house that fell short of what I need.     

[bAdbOb]

Possibly here:
http://hayesinstruments.com/