Great Crusade Markings for Space Marines - A Study...

This week I received the next two volumes in the Horus Heresy series by Forge World.
They are massive tomes which primarily concentrate on the conflict between the Emperor and his lost son, Horus. But buried in the pictures and text are some clues to the markings Space Marines of the Great Crusade would have worn.
The Great Crusade is an era lost in time, but if you want to do an army from this time, finding markings and information is very hard. My War Hounds army has stalled due to lack of information on exactly what they would have looked like and how they acted.
I am hoping that this entry using the Forge World books will be a point for people to add and discuss the markings across the spectrum of Space Marines during this time.
If you think I have made errors or you can hopefully add to it, please do! It's so hard to find good info, so share the love. 

The vast majority of Great Crusade markings seen in the Horus Heresy books are the Raptor and Lightning Bolts (Raptor Imperialis). This was the symbol the Emperor of Mankind used before the double-headed eagle was adopted.

Below are a selection of Raptor Imperialis used by different marine Legions. "Z" lightning bolt is the common feature amongst them all, notice the pre-yellow colour scheme of the Imperial Fists with the symbol in a circle. This would have been used during the Terran Unification campaign, as their armour become yellow as they spread through the Solar System and were reunited with their Primarch.

The Imperial Fists feature prominently in this article as they seem to have used the Terran Unification symbols heavily. Other Chapter are similar, but variants are noted.

Terran Unification Salamander

Terran Unification Iron Warrior

The afore-mentioned pre-Imperial Fist livery showing a Terran Unification symbol.

Even the Luna Wolves, soon to the the Sons of Horus were proud to wear the Raptor Imperialis for the Emperor.

A variant off the chest of an Imperial Fist. This would have been likely during the Great Crusade, but post-uniting with their Primarch.

A very popular MKIII embossed lightning bolt design. This is actually included on some of the MKIII Forge World Marines

Another variant of the Lightning Bolts - this time on a Contemptor.

A variant of the Terran Unification symbol - this one is Raven Guard, using a skull instead of the Raptor

Here the Lightning Bolts are integrated into the Fortress Defence symbol of an Imperial Fist

This is a Terran Unification campaign badge for the Hangman's Void campaign.

Rank Insignia During the Great Crusade

Veteran Sergeant (diamond signifies veteran) chevron from an Imperial Fist

In the beginning (Rogue Trader in fact) Games Workshop had rank insignia displayed on Space Marines. Then in the 90s sometime, this all stopped. Some Chapters went with only helmet stripes or colours, but the insignia was punted! 
Well with the Horus Heresy back, Games Workshop and Forge World have brought the old insignia back - or at least some of them. 
Below is the Space Marine ranks from the Space Marine Painting Guide in the very original Space Marine Painting set.

At this point it seems the Sergeant is the only one really using this old system, but it will be interesting to see if the other ranks do appear with these.

Great Crusade Veterans

The following are from Imperial Fists celebrating their role as veterans of the Great Crusade. These would likely not have been worn during the Great Crusade itself, but maybe a version of towards the end...?! These would have been quite prevalent on officers and Veterans during the Horus Heresy.

Conclusion

I hope this article has been helpful. If you have anything to add - please contact me so I can add it.
I think as a community we can get a pretty definitive collection for those interested in make a Great Crusade-era force. Even if it's just for general interest, this community is very good at this kind of stuff.