Those NOS bars are the second design Lakewoods-top bar pinched down and the boxing plate added. The original Lakewoods used the round rebar style inserts just like the NMW's and you could not tell them apart unless you compared them side by side...and they may have been identical.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: YENKO DEUCE REGISTRY</div><div class="ubbcode-body">I think it is difficult to tell sometimes, but yours look like NMW's - although Lakewood's may have been made by NMW.
FWIW, here are Lakewood bars for a Chevelle;
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