Hope lever nut size and help

I bought a set of hope brakes a while back, hoping to throw them on a build for winter use.

First up, what are they? I think mini, just want to be sure.

Second q, one lever is missing a nyloc nut. What size do I need to replace the missing one?

Finally, I have a tasty set of early mini brakes that are unusual as they appear to be factory anodised in turquoise and purple. Even down to the 6mm hose mounts. Never seen another set like them, wondering if they were anything special, special order, team issue, show bike etc? I plan to use them, but I would like to tune out some play in the levers. The brass insert moves a fair bit and a new one from a rebuild kit doesn't help. They are older, so wondering if the design changed and the brass insert was larger on them than the newer versions, and the previous owner may have replaced them with the wrong size? Or has the lever simply developed play through time? If the latter, is there a cure? If the former, are spares available? If neither, can I get replacement purple levers, or even silver ones which I'd get anodised?

Some pics:

I'd be surprised if it's not some M5 or M4, but wtfdik.

If you measure the bolt, that should give you an idea.

Defo M5 nyloc nut.

M5 locknut
Part number - HBSP19
The nylon insert - HBSP99

Same fittings as of the mono mini and mono lever

Can we have some more pics of the purple/blue Mono Minis please?

They’re truly unique, likely made for a show bike or re-anodised by someone. Note lack of laser-etched Hope logos on the master cylinder.

Mini lever blades are no longer available to buy new; best option would be to hunt down an old set second-hand in decent nick and have them re-anodised.

Earlier brakes I think they did the logo first, theen ano'd the whole thing, possibly to preserve the anti-corrosion effect of the anodizing.
Hence.
https://www.ebay.co.uk/itm/vintage-hope ... true&rt=nc
Ive one of these in blue and the ano over the logo is the same.

You can usually tell on the inside when its missing from seal recesses

The caliper in your eBay link is an earlier model which has the logo machined, not lasered; the ones ishaw posted are later ‘Mono’ unibody calipers.

I was referring to the lack of lasered logos on the master cylinder in the photo of the purple/blue brake.

Here are a couple of other pics.

Logo on top speed is clear, maybe original, no idea.

Calliper logo is not clear, and it looks like a layer of clear has been applied to them as they are shiny and smooth like lacquer, strange!

Ah, that looks like they've been bead-blasted and re-anodised. Very cool colours nonetheless!