1935 Dutch "Zucker" Rocket Flight Covers?

I have dug up these rocket covers and thought i'd share.

Not to sure about these? Not my collecting area but would like

a catalog reference if anyone has a reference link or a scan it

would be appreciated.

I did find an informative link to Zucker here.

http://cabinetmagazine.org/issues/23/turner2.php

Q:Would this be Rocket mail or torpedo as the Zucker rocket

engine was used to propel the torpedo.

The bottom one is damaged possibly salvaged from rocket?





Regards

JC

Hi; Quiet interesting article and history.These are nice covers from Zuckers early period.I'd keep them. Another link below..
http://www.astronautix.com/z/zucker.html
ebay seller nordphila has this literature:

People who would like to collect rocket mail should buy one (or both if you are really into it) of the two major catalogs that are out there that cover these interesting covers. The newest one is "Pioneer Rocket Mail and Space Mail" by Walter M. Hopferwieser. The older one (from 1967) is the classic "Ellington-Zwisler Rocket Mail Catalog Volumes 1 & 2" The Ellington-Zwisler one can be pretty pricey though.

These were offered on "Gumtree" (Australia) this week for $1
I made an offer of $3 but never heard back, probably sold.

Update: just rang the vendor, still for sale (Advert was $1 negotiable)
on enquiry, he wants bids to start around $200

Further reading
https://goscf.com/t/12683

Fabulous Air mail Livery, around the border of the cover, Smauggie.
That's a new design for me.

While I'm waiting for my catalog.

Belgium Rocket Society.Charles Roperti. CDS hard to read.

Here's some more.