Its all good weejohn, always the simplest things are overlooked. I only thought of checking as I was reading through random threads (mostly 5e conversions) and came across somebody mentioning a similar problem and that they had a broken cable. Thought to myself that theres surely only so many things that would stop a gear being selected. Lucky really as I was debating to buying a gearbox
Edit: What would be the best way to check them? Is it a case of taking them out and checking or is there a quicker way?