Please clarify your Nuke and phpbb version
I was successfully modify one theme for arcade
here
http://game.thaihealth.net
(thai lang but have a link to chnge language)
I think mods should be on both
forums/template/subsilver (or yourtemplate)
themes/forums/
-whoisplaying body.tpl
-toparcade body.tpl
-statarcade body.tpl
-scoreboard body.tpl
headingarcade body.tpl
hall of fame.tpl
games body.tpl
comments select body.tpl
comments new body.tpl
comments list body.tpl
comments body.tpl
arcade cat body.tpl
acade body.tpl