Gettysburg: The First Day

Well, the paint is now flying here in Old School ACW Headquarters.
All my recent orders of figures have now arrived and I'm getting going on painting the little beggars.
My Union regiment has now been joined by a Confederate one and I am about to start work on a second Union unit.
With our friends the Confederates I've made a classic wargamers accident/mistake/move insofar as I have painted up one Infantry regiment and also figures for Robert E Lee and JEB Stuart. Shades of the first regiment of the Imperial Guard commanded by Napoleon and Ney! Still, it was what I had to hand at the time...
Now, I want to talk a little about the first day at Gettysburg. This is the scenario reproduced from the Wargame Digest in The Wargame Companion and I want to take a look at how it matches up with the battle.
The two armies began to collide at Gettysburg on July 1, 1863, as Lee urgently concentrated his forces there. Low ridges to the northwest of town were defended initially by a Union cavalry division under Buford, which was soon reinforced with two corps of Union infantry. However, two large Confederate corps assaulted them from the northwest and north, collapsing the hastily developed Union lines, sending the defenders retreating through the streets of town to the hills just to the south.
As Grant has it, the Confederates are represented by 10 infantry regiments and three guns, while the Union has six infantry regiments, two of cavalry and also three guns.
He limits his battlefield to Seminary Ridge to the west, Cemetary Hill to the south, the Baltimore Pike and Culp's Hill to the south-east and east respectively and to the north the area past Barlow's Knoll.

The scenario calls for the Rebels and the Union troops to come onto the table at specific points on the game. Grant considers the length of the day to be 30 moves. Remembering that a brigade is two regiments and a division two brigades:
Start of the game:
A Union Cavalry Brigade and a gun anywhere on the board.

Move 1 - a Confederate Brigade with a gun enters at Cemetary Ridge.
Move 6 - a Union Division and a gun come on the table via the Baltimore Road.
Move 8 - a Confederate Brigade with a gun enters play from Cemetery Ridge.
Move 12 - a Union Brigade plus a gun comes on via the Baltimore Road.
Move 15 - a Confederate Division enters play (gun in tow) down the Carlisle Road.
Move 19 - a final Confederate Brigade comes on via the Harrisburg Road.

These deployments seem to match the timing of the main Confederate attacks so far as I can tell with my imperfect understanding. The relative sizes of the opposing forces also seem about right.
I think we have a fairly useable scenario.