Okay so I have melted my high/low beam switch, A previous owner had fitted H4's and I didn't give it a thought until it was too late.

My Question is... Can I use a similar honda switchgear as a donor for a new switch ? i.e. one like this:

http://www.ebay.co.uk/itm/131330088678? ... EBIDX%3AIT

Yes. And no. I don't see why a similar set would not fit on the bike assuming the bars are the same size. BUT - it's highly unlikely that many if any of the pins are in the same place and the same things may not be on the same connectors. Also, the wires may not be the same length. At the very least, you'd probably have to attempt to take the pins out of the existing connectors on both and swap them over. Or, if you are confident in such things, you might be able to extract the hi/lo switch from the donor set and solder it into your existing switchgear. Be warned though, the switch has one of those useful 'pingfuckits' in the mechanism, so take it apart in a bag or you may lose the spring!

'pingfuckits' - classic. Found a few of those in my time.

Yeah a few years ago I had one of those moments taking my switch apart in a garage filled with years of storage. It went no more than four feet but took me ages to find it. Its not too hard to swap pins but choose your switch carefully as the hi/lo may also be fried on your replacement. As I found out one eBay purchase later.

Thanks. I'll buy a cheapish switchgear and attempt a switch swap.
And unfortunately, your warnings about the spring come too late to help me, it has already "pingfuckwitted off"

If you have a high/lo switch (just the plastic sliding bit, not the switch itself) left over, I would be keen on it :-)