After doing as much research as I could I decided that the arguments for trying an antibiotic regime were persuasive enough for me to try.
Consequently I met Dr Wheldon (Incidentally he's a very nice chap!). Armed with a prescription I started 200 mg / day doxycycline on Saturday (02/10). I haven't started the roxy yet as that had to be ordered.
I can't report any results yet as it's too early to tell, however I will post regular bulletins on progress.
I will try and make those reports as honest as possible, reporting both good or bad without editorialisation.
A little personal info on my MS:
Diagnosed for 5 years with RRMS, recently upgraded(sic) to progressive.
Still able to walk unaided for approx 100 yds before needing support / rest
Severe spasticity / Ataxia
The usual bladder problems

Burning / tingling sensation, both legs from upper thigh downwards.
Those are my major symptoms, any changes either way and I'll report them.
Robin