Discovery 1 Anti-Roll Bars on a Defender

A few years ago I saw some Discovery 1 ARBs on eBay for cheap and thought I was getting a cheap way of getting bars for my 110 TD5 given that the D1 was, as I understood, pretty much a Defender underneath. I've just got round to cleaning them up and bought all the fittings thinking they were basically identical to the Defender ones. I purchased all the rest of the parts according to the JLR parts diagrams for a pre-2007 110. Two things have come up.

1. The front (smaller) bars have two M10 holes rather than one M16 on each side. I have a choice between getting the D1 arm and trying to fit it or drill one of the holes to M16. Since there's a rather generous amount of metal around the holes I'm going to size them up and find the best way to drill a bigger hole through whichever one I decide is best.

2. The bush holder things that hold the arms to the chassis are confusing me. So the bigger thicker bar is the rear ARB, and the thinner smaller one is at the front. My rear chassis has the brackets to mount on and each side has 4 holes for the installation. At the front each side has two holes. In the order I made I got a pair of brackets with four holes each and matching bushes. I also got a matching set with two holes; so I thought a set for the rear and a set for the front. However, the set with four holes, that I thought would be the rear, only fit the smaller diameter, so they look like they only fit the front bar. And the set that I thought would be for the front have a larger diameter, only fitting the bar for the rear. What's going on here?

Sorry, I hope this isn't too confusing, but that second problem is throwing me. I don't mind doing another order but I don't know what part numbers to use now.

Okay, it took me far longer than I care to admit to realise that on the Defender the thicker ARBs are at the front and the thinner are at the back, which goes against all my understanding of ARBs and seems really odd considering that the back rolls more than the front. I spent an evening looking into getting some bushes that would fit but in a fleeting moment of sanity I bought some refurbished Defender bars off eBay. I've got enough jobs left to do without causing myself a load of pain trying to get the Disco parts fitted.

Well at least others may benefit from your info.

Front & rear are totally different shapes the U shape one goes to the rear. I chucked 2 sets away as I fitted 4 link kits.
My other disco was lifted & I made 50mm lowering blocks out of box section to stop the rear one from flipping. Got
pics somewhere.