Hi Michael...Not being totally familiar with the Indian replicas I don't know of a 'giveaway' difference. I am told the Indian replicas are quite good, but...
Most likely differences (apart from the basic dimensions, hole positioning etc.) will be material gauges, details of the D rings,ring brackets and rivetting and details of the side arms and rivetting. A few pictures and dimensions will probably be needed to determine whether yours are originals....Ian
email (option): ian@wright52.plus.com
The trouble is that "Originals" were made from the early 1940s until the 1960s, I have one frame dated 1957.
They were made by several companies and were available new on the civilian market after the war, and they varied a lot in style.
Since then lots of companys and individuals around the world have reproduced then in varying quantities and qualities.
So its not just a case of "Original WW2" or "Indian copy".
Rob
email (option): robmiller11@yahoo.co.uk
It looks like it may be another part on the 'fitted post war' list along with rear frames, MU42 headlamps, MCR2 regulators, Later dynamos?, post war horns,fire extinguishers, green pannier bags?, postwar registration plates, workshop plates, batteries..etc. etc.?..and all of the above could be justifiably described as 'original fitment' during the service history of the bike and therefore 'Kosha' fitments.
Life just got more complicated...a rivet counters paradise!!
...Ian
email (option): ian@wright52.plus.com
Bloody hell.... 
Well I just straighten mine up and forget about it. They cant be that horrible far from something good then. I'm also guessing there is nowhere to buy those large wingnuts?
email (option): micran1234@yahoo.com