Hi Rob1n (Robin?)
Better late than never I suppose, here's the picture I promised you with one or two additions by yours truly.
If you don't have this, then you may struggle to get the plugs out.
You could manufacture your own easily enough though, if you can lay hands on an old 19mm box spanner from a car boot or auto jumble and a 10 or even 12mm hex bar or old alan key - perhaps from same place.
You'll also need a rivet (or even a thin wire nail or panel pin if no rivet available).
Ideally you'll also want a black rubber tap washer or similar (colour optional)
It doesn't matter about opposite end size of the box spanner as you'll need to cut it in half approx (use dimensions above to know exactly where to chop it).
If using an old alan key, chop the long side at approx 75-80mm, if using hex bar then same length required.
You could probably get away with bar being a little shorter and box being a little longer, but your overall length needs to be 137mm ish to give you the reach into cylinder head recesses.
Drill the hex bar approx 10mm in from one end and the box spanner approx 5mm from the 'dud' end - use a drill bit which suits the size of rivet you have available - the OEM one is approx 2mm.
Fasten hex bar into 'dud' end of box spanner using rivet (or bent wire nail). Then slightly flatten or mishape box spanner to hex bar - you're looking to get a slightly oaval shape.
This shape gives greater flexibility for the plug spanner to get in - on the OEM one it's approx 35 degress from centre in 2 directions.
Finally drill or shape a hole in tap washer (2 glued together may be required) to allow thread or plug cap to fit in - the hole ideally needs to be wide enough at the plug end to just allow the top of the ceramic part to sit in there. I assume this is to allow the plug spanner to grip the loose plug long enough to get it into or out of the cylinder head.
You could just nick the rubber insert out of another 'cheap' plug socket and cut to size.
Oh and by the way, the plastic coated metal band isn't standard Firestorm kit as far as I know.
HTH
Graeme.