L.A.B. wrote:The Hepolite brand name is now owned by Wassell.

http://www.totalbikebits.com/wassell_history.html

In 2011, the Company acquired the Hepolite brand, trademark and goodwill from the Federal Mogul Group. Originally Hepolite was a brand name of Hepworth & Grandage, who later merged with Wellworthy Pistons Ltd, to form A E Piston Products Ltd.

I believe these "new" Hepolite pistons are made by JCC.

I got JCC pistons for my 750 in Emgo boxes.
Quality looked very good and came with rings, wrist pins, circlips.
Very happy with performance and so little oil consumption can't hardly measure it.

Gripper,

I have total seal, but these are in the second groove only, in US made short skirt pistons out of a Jim Schmidt rod & piston kit. The TS rings do make the pressure on kicking her over much firmer, you can show off to your mates, and stand on the kicker and it will support your body weight. They also seem to help cold starting, as they draw up fuel real good.

Cheers Richard

My 2 cents worth
Here are some pictures of what ZFD posted. These are out of the 750 Commandos that I am restoring. these are both AE marked Hepolite pistons. The piston on the right in the photos is from my 68 750 that is for my Commando R replica. The piston on the left is out of my 71 750 Roadster. The piston on the right has the horizontal cutout that joins both slots. The 3 slot pistons are marked 160001 on the crown. The later 2 slot pistons have un-slotted ring groves and lack the 16000 number on the crown.

Back in '72, one day in Griffith Park, one of the OEM pistons as originally fitted in my first Commando, a '71 Roadster, came apart at about 7000 miles. Made an awful racket.

On tear down, reading the parts, the piston split into two pieces, crown and skirt, then the valves opened and sort of pushed that crown back down and then the lower half of the piston would push that crown back up into the chamber and then the valves would push it down again. Rings stayed in place, didn't hurt the bore or the chamber, just bent the valves and scuffed the squish area.

I was dissappointed with Norton when I saw those stupid oil slots. Why? other manufacturers used small chamfered holes.

Comma oil slot piston let go was reason for Trixie Combat '07 2nd rebuild, but was aggravated by also being rubbed on by Al gasket stuck in before me time, which was only 3 wks after 1st rebuild d/t deer strike doing everything else but engine and tranny which were fine the 1st 3 wks before dam deer. If any Al alloy part in a Commando has a life time heat cycle and flex limit its these obsolete pistons. I not longer consider it an economy of effort not to pop the top off an otherwise unknown fine running Norton. ugh.