The KV-2s are about the only ones I don't have of the Trumpeter KV variants so I can't tell you how it looks. However, Neil makes no mention of the welds needing any changes in his review on 4BOgreen:
http://www.4bogreen.com/kv-series/plastic-and-resin-kits/1-35-scale/trumpeter/00312-russian-kv-2-tank
I'm therefore inclined to believe that the kit welds are fine. The site is a very useful resource for the KV series by the way, in case you were unaware of it.
Rob
There's nothing cushy about life in the Women's Auxiliary Balloon Corps