something I noticed when building the new Saturn V

the new molded LEM shroud has a shock cord eye. Neither tube is a standard size.
the LEM tube is just smaller than a bt 60. It would be hard for the regular scratch builder to use one.
I wonder if they have plans or the tooling was just easier.

I’m going with “they have plans”, although I have no inside information.

They are standard tubes...this body tube reference is very handy to find tubes and lengths for Estes kits. Look for kit 2157.

I have attached a drawing of the Centuri KS-12 Saturn V this is the basis for the Estes 2157 and 1969 kits. The tube lengths I measured on my old kit are slightly different than the lengths listed for 2157, probably due to different construction techniques.

The CS/SM tube is a BT-58. The SIV-B (third stage) tube is BT-80. The main tube is BT-101. These are available from eRockets (Semroc) among other sources.

The specialty size was probably done to conform to the 1/100 scale. Having said that, they have been known to use surplus parts in newer kits. The recently released Red Nova uses the nose cone (less tower) of the Ansari X prize Thunderstar. So we could see that transition in future kits if they have an excess they want to get rid of, i.e. more SPEVs.

Don't forget - the new molded LEM shroud could be used on a 1/100 scale Saturn 1B.
(Wishful thinking on my part)