There appears to be a regimental museum in the old barracks, Bodmin, which must surely merit a visit.
If I remember rightly your previous posts place you in Germany. I am unsure whether the British Legion function there, but if they do they could be able to put you in touch with a local contact or two who might be happy to share some tales. Not necessarily from the exact unit, but there should still be a few light infantry men, and some who were in other units but the right campaigns.
Of course if you are UK based the Legion will be more likely to be able to help. How willing they may be to help will doubtless depend on whom you encounter, and on your ability to demonstrate your bona fides. I would expect them to be at least a bit protective towards these now elderly men.