If you have some of the parts, you may be able to piece them together. I found a few pieces at British Only in Garden City, MI. The parts you're looking for are:
Brake and air lever complete 06.0690
Clutch lever complete 06.0691
or parts:
Brake lever only 18-754
brake body 06.0061
lever pivot screw 18-087
pivot nut 18-053
air lever 12-256
air lever body 12-619
air lever central body screw 12-607
air lever cap 12-606
spring washer 12-033
body clamping screw 11-013
other clamping screw 11-014
clutch lever only 18-752
clutch body 06.0062
pivot screw 18-087
nut 18-053
body clamp 12-595
body clamp screw 11-014
The clamping screws and nuts may be sourced as standard 1BA items I think, the pivot screws are shouldered, so are special. I found some levers at Walridge, the clutch bracket, some pivot screws and air lever base at British Only. As I remember they only listed a few pieces and I either emailed them or called them and they did have some other old stock parts not listed on their web page. Walridge did claim to have a source for 'close enough' lever sets, but I never got them because I managed to piece them together, he may have some parts too. I did find a pair of levers at Hawkshaw in UK that looked to be a very close set too, but I had already started getting parts. It took me nearly a year to piece them all together. Make sure you get bodies that have the threads in them for the adjusters, not the slide in type, you need to specify. Since the picture was taken, I have replaced the clutch body because it had been sawed off short from damage. The parts are out there if you keep looking. Try Burtons Bits too.
Dave
69S