Special Interest Group

The special interest Groups (SIG) are exhibitions of models about a given theme displayed outside the regular competition. Participating in a SIG is an excellent way of taking part in C4-open without any pressure to compete. Everyone is welcome!

2025

SIG – The Aircraft of Kelly Johnson

In this SIG, we highlight one of the world’s most influential and prominent aircraft
designers: Clarence “Kelly” Johnson, the well-known (and sometimes notorious)
head of Lockheed’s Skunk Works.
And why are we doing this? Well, Kelly Johnson had parents from Skåne! His
parents, Peter Jönsson and Kristina Andersson, were emigrants from Malmö. So he
was almost a Malmö boy!
As the leader of Lockheed Skunk Works for over 40 years, he played a key role in the
development of more than 40 aircraft and is considered one of the most influential
aircraft designers in history.
He is best known for designing iconic aircraft such as the P-38 Lightning, F-80
Shooting Star, Constellation, F-104 Starfighter, U-2, and SR-71 Blackbird.
You can see all the aircraft he worked on—and which could be included in this
SIG—here: Kelly Johnson (engineer) – Wikipedia)
Contact Jacob de Maré if you’d like to join! Jacob_de_mare@hotmail.com

SIG – Centurion

The SPHF Centurion Interest Group – CIG

The Swedish Armour Historical Society (SPHF) will be hosting a Special Interest Group – or rather: Centurion Interest Group – on C4-Open 2025.

2025 marks the 80th anniversiary since the first Centurion pre-production vehicles reached British units for evaluation. To commemorate this, the CIG will be open for entries of the whole Centurion family in any scale, any variant – including special vehicles – and of all users/nations.

We hope to be able to display a large cross section from the history of one of the most famous cold-war-era tanks, including a lot of examples from it’s long and faithful service within the Swedish army.

If you have Centurion models sitting on your display shelf, we hope you would consider bringing them to C4-Open and the CIG this fall. There is no limit to the number of Centurions you can enter. As an extra motivator, the Swedish Armour Historical Society (SPHF) will draw a few winners of SPHF club prices among the entries. Sign up for the CIG by sending an e-mail to Erik von Rosen: evr(at)telia.com.

See you at C(-enturion)4-Open 2025!

SIG – Vietnam


This year marks 50 years since the fall of Saigon, so in this SIG we remember the Vietnam war from 1954 to 1975. All related subjects are welcome, from aircraft to armor and to G.I’s on scooters and both military and civilian subjects.

Contact Patrik to be a part of this SIG.

SIG – Jeep

The Jeep and his cousins

There are few vehicles more iconic than the “Jeep”. It was born in 1940 and has since been used in many forms all over the world by both military forces as well as civilians. It has also been copied by many companies as well. In this SIG we welcome not only Willys Jeeps but Ford Mutt, Bantam, Hotchkiss, Type 73 Mitsubishi, GAZ 67 and other close relatives of the Jeep. Note that more distant relatives like Kübelwagen, Landrover, Landcruiser and Hummers dont fit this SIG. If you wonder if YOUR model belong to the SIG, don’t hesitate to send an email to me. Those who want to enter the SIG, please contact me so I can make room.

Contact Erik Ahlström to be a part of this SIG.

Once again, welcome to this year´s SIG:s!