Aye Richard,
Commisserations!
Been there with other engines and it appears that with engines of this era a complete engine rebuild for under £500 is cheap. Unless you have the engineering facilities and experience to do the machining. Most places these days are at least £40 an hour for labour even one man bands, unless they are retired and doing for it a 'hobby'.
I am pretty sure it would be possible to bush the little end, but not having the engineering training, I am not sure of the practicalities of specific materials and it all depends how much 'meat' is around the little end eye. But, clean up the little end of the rod, bush it with a phosphor bronze bush, drill the oil holes and then ream to give a tight but smooth fit, as per Honda spec sheet for the motor.
Alternatively, a new rod and a crank rebuild as the big end may have suffered when the little end nipped up. All speculation, unless evrything is closely examined. I use a watch makers loupe x 10 magnification, after washing down with brake cleaner.
You can see in the two attached images some of what I faced with the XT600E engine for the SRX400 Mono rebuild and it was still running!
There was getting on for 3mm play between the inner and outer races of the nearside main bearing and rust build up on the offside crank journal. The fifth gear pinion had pitted teeth and the resulting swarf, along with silicone gasket and fluff from rags had half filled the oil pump strainer and there was still plenty of metal sitting in the bottom of the crank cases. All in, the spares, a crank rebuild and barrel hone cost nearly £1,100, my time was for nowt and this was three and half years ago.
All the best, Bill