The delay in producing them was caused by a change in the law (in reaction to exploding batteries on airlines)  that meant I can no longer get the lithium ion batteries I had previously used.  So now I can't source the ones I need to fit the printed circuit boards I have had made. So I need to cut battery tabs down with small scissors, the first fifty taking a long time to do. If indeed I do make a new batch I will change the technology so it runs on capacitors so you can recharge thus enabling me to move away from batteries all together and still have his eyes to light up.