If you look at the images below, you can see the differences.
On the Jackal 1, the weapons ring is lower down, level with the the top of the roll cage. It is also located further aft than on the Jackal 2.
A Jackal 1 has no running boards along the sides.
The spare wheels (one either side) on the Jackal 1 are fully exposed and visible, whilst the Jackal 2 has one spare wheel and it’s hidden inside the side door (under armour).
Note that Jackal 1 has roll bars that run over the top of the side doors, whereas the Jackal 2 does not have them.
In the rear cargo bed, the configuration is different - the Jackal 1 has a distinctive ‘box’ frame that fills most of the rear area and is usually fitted with a fabric cover - the Jackal 2 has a smaller box and more general cargo space.
All images below are mine.
JACKAL 1
JACKAL 1 and 2 - In the foreground is a Jackal 1 (one of the prototypes without external armour). Compare the location of the weapons ring on it with the Jackal 2 in the background. Ignore the raised roll bar over the cab of the Jackal 2 - that’s a later addition and can be seen on both types of Jackal.
JACKAL 2
