As for the tail hook itself, Graeme was making a resin one that was part of his kit. I used this one for mine. We have not had time to produce one as yet, but I would like to in the future.
Gear. The Corsair gear has a very small degree of cam over to lock it down. This is necessary or it would not unlock properly without some sort of spring. When new, this is fairly reliable. However, after parts wear in, the slightest slop in the mechanism can be enough to allow it to unlock on a good backward motion landing strike, as you would have in a slightly tail high touch down. A loss of air pressure as in a slight leak makes all this even more likely. I say this from experience with the stock system.
First, the electric conversion will not allow the gear to unlock even under less than perfect landing strikes because the scissor will not move unless the jack screw turns. Second, the electric gear moves in a much more scale way, even with air restrictors in place. Third, you can cycle the gear as often as you like, as you need to in competition for instance, with no concerns like you would have with air.
I have been flying Down and Locked electric conversions for over 4 years with not a single gear failure. No belly landings or controlled crash landings due to gear issues. None. I can't say this with most of the air systems I have had over the last 45 years. And I maintain my stuff. I was so glad when I was introduced to Mitch and his team at Down and Locked and saw what they could do for us who use retracts.
My planes are detailed and expensive. I am hard enough on them without adding gear failure into the mix.
Now, you will have guys claiming they never have problems with their air gear. OK, I'm happy for you. In the REAL world, at every event I have ever attended, I have seen gear failures with air gear and this include places like Top Gun where it happens to some of the very best builders. The damage ranges from minor to more often moderate, and sometimes even crippling. If you have been in the hobby for awhile, you have seen this yourself. I have been using retracts for almost as long as I have been in the hobby. Remember Rohm, and Spring Air? Glad we have progressed away from those days. Was never the same after we could no longer use Freon.