Several kits are presently marked "out of stock". Most of these are because the kit uses photoetched parts and I have run out of that particular photoetch. The 1/72 Mercury Redstone and Mercury Atlas and Soyuz TM kits were on that list, but are now available again as the photoetch has been resupplied.
Other kits will become available again soon. Part of the problem is that the people who do my photoetch have been going through some tough family medical issues and so production has been delayed. So to accommodate this, I have been only reordering small batches of resupply to them. The parts yield on the sheets for these kits is high, so I started with them.
Some people have inquired about the Saturn 1 and 1B kits. They are out of stock because I am out of the brass tubes that make up the first stage. I have contacted the supplier several times and have not as of yet, gotten a response. If I have to conclude that I will be unable to get the tubes anymore, I will have to redesign the kits in some way that doesn't require those brass tubes. But in any case, the Saturn 1 and 1B kits will be available again in the near future.