OM1 CLA'd by John Hermanson?

[nikku]

actually there is one issue - meter underexposes 1 stop (maybe even 1.5). Not a big issue - remedy is to set 200iso when I use 400iso film, but I wonder if it's plain malfunction, or was done on purpose in CLA process, for example adjusted for 2 series screen maybe?

Did you put the proper battery in? John H adjusts the meter to take an SR44 battery when he does an overhaul. Could also be adjusted for a 2 series screen.