I never got around to the PS-2 upgrade for my K-Line hudson yet, but JDS did upgrade my O-27 Polar express engine. They installed a smoke unit, cab lighting, engineer and fireman, green marker LED's and a LED head lamp. They made my little toy engine look like something special.
If you search Polar Express upgrade, posted by GG1 man on 02/25/2012 you will see a short vedio of their work.
I would say that they do very good work at a resonable price.
https://ogrforum.ogaugerr.com/t...ine-with-jds-upgrade
Try the above link.