The little angled rubber hose from the carb to aircleaner was hard to find for a while, but are now being made in repro. Ebay has them listed all the time.
Search ebay with searchwords triumph trw hose. Here is one listing in the USA:
http://www.ebay.com/itm/Triumph-TRW-...488b2f&vxp=mtr
If you are more discerning and want NOS (which means 40 year old rubber) here is a source in the UK:
http://www.ebay.com/itm/TRIUMPH-RIGI...item35d870bebc