Not much use rebushing the idler gear, it's well worn (no teeth left), fortunately it's not hardenned so the drive gear is fine. However, I've checked out the Hardinge US site and they have full parts lists for the HLV models including the HLV/EM. As the feeler looks like a pretyy exact copy I'm going to order the idler gears and pins direct from Hardinge. Hardinge UK tell me they do spares for the HLV so maybe I'll strike lucky and not have to order from the US.
You can find the full Hardinge Parts Lists at the follwong URL: http://www.shophardinge.com/partslist.aspx

I think, following Tom's advice. I'll strip down the entire saddle and replace any worn parts whilst I'm at it. There's a pretty good bearing place close to me and I should be able to get all the bearings over the counter. Looking at the parts list, I'm surprised how many bits there are. My previous experience is on a Myford Super 7B so I'm really looking forward to much more accuracy and better finish when this is done.

I'll post more pictures as I go.