An exhaust specialist could make one up for you and fit it to the car
Nothing too difficult about them - just a barrel silencer and tail pipe. Let me know if you need photos and or dimensions.
I had one made up a few years ago for my 1972 4/4 in 1 3/4" stainless. Silencer cost £120 and tailpipe was £65. Written lifetime guarantee as well.
Just make sure that the mounts are sound. 4/4's of that age use a single bolt bracket which works loose and causes the hole in the chassis to wear oval or a nice star crack to form. Much better to modify the exhaust mounts so you have the bracket secured to the chassis by two bolts.
Arwyn
