What keyboard is it? A4000 with the small DIN plug? I've never seen an adapter for that one before, but as someone else pointed out - shouldn't be too difficult to hack your own. There *were* adapters made commercially for the A1000 to use A2000 and A3000 keyboards though. I had one once upon a time. I seem to remember Redmond Cable & Micro R&D selling 'em.
