Ok not counting Incarnate stuff back in the day pre-incarnate we ran an all scrapper stf the person that ended up tanking recluse while we worked on the towers was a broadsword/shield they where softcapped and then added parry to stack probably want aid self if you go that route. The other option imo while rad is good I still think katana/wp is the other way to go stack DA and note Iggy soloed the itf with a katana/wp per-incarnate.
Now the second scrapper you want dps and pre-incarnate if you look at the top dps build for st on the tower test the top slot was dm/sd I made the top 10 with fire/sd the nice part about dm/sd you have a heal built into your attack chain and with spring attack now you have an aoe to mix in with your st prowess . With DM you can leverage the repairman as fodder for soul drain buff along with shield charge /spring attack.
Just my two cents from the past