You have probably found out that the Redditch-built REs were sold under the Indian name in the USA in the late 1950's, so instead of Royal Enfield Bullets, Super Meteors, Meteor Minors, etc it was Indian Woodsman, Westerner, Apache, Tomahawk, etc. The Indian Chief which grumbern has almost finished restoring is therefore a dressed-up Royal Enfield 700 OHV parallel twin and not the big flat-head vee twin made in the USA.
A bit of a side issue, but when it comes to the 500 singles there can be some confusion when talking about about Indian Bullets, ie Indian-badged Bullets built in the UK and shipped to the USA, or the more widely available (Royal) Enfield-badged Bullets built in India.
A.