Here's a collection of photos of the Simbas, or more accurately soldiers of the Armée Populaire de Libération. This is the best of what I have been able to find so far.
The army was in theory divided into regular units. Like the ANC these were unités d'operations and unités de garnison. Additionally there were irregular militias called barriéres.
The Simbas were typically well motivated but lacked discipline and their command was often chaotic.
Some Simbas were termed 'Jeunesse', i.e. youths or young ones.
These next few are stills of Simba prisoners from the the movie Africa Addio. There are some accusations of staging against the film but it looks pretty authentic.
I used the Gancia t-shirt from the screenshot above as inspiration for painting the Simba in the centre of the group below.
I added a Simba style monkey-hide hat similar to the one worn by this 5 Cdo mercenary to a TAG African Militia figure.
This last still is the only one I could get of an armed Simba in the movie. The live Simbas are only seen moving rapidly at distance. Very sensibly in my opinion, given the copious rifle and machine gun fire coming their way. Interestingly he looks to be carrying an FN FAL or possibly a G3. Most of the Simbas above look to be carrying older Mauser types or FN-49 rifles.
These are some of the Simba leaders. To start is Patrice Lumumba, the first prime minister of an independent Congo. He was deposed and murdered after just a few months in office. The Simbas fought in his name.
From left to right. Jean-Sébastien Ramazani, Laurent Kabila, Gaston Soumialot and Adrien Kanambe.
Nicholas Olenga
Président Christophe Gbenye, left, and Général Olenga.
Pierre Mulele, who had trained in China and led a Maoist faction in Kwilu province.
The famous Cuban revolutionary Che Guevara arrived too late in the fighting to effect much actual change but has great what-if potential for us wargamers.
These last couple are from later after the fall of Stanleyville, when the Simbas were reduced to a hard core of guerrilla fighters in the jungles and mountains.
Sadly, nobody makes any 28mm miniatures of these unique fighters except Grubby Tanks and they just take your money without ever sending you anything. So, I have had to find substitutes or try some conversions.