IIRC, I couldn't find decals for this, either. The markings looked simple enough, so I picked up a couple of sheets of green decal film (one lighter sheet for the topside 'faded' look), cut out the squares and circles, spun up my courage and hand-painted the funky numerals. It probably still needs some stencils. Yeah...next time.
I always thought of these jets as 'cat food.' I'm sure you remember why.