Did you use the Spares list from the ADS Pleasure Driving Rules? Those are required for showing in approved shows, if you plan to do that. I find the items there pretty handy for any driving you do away from the barn. And of course you can add things you find handy, because of something you experienced. You might want to consider carrying a box or basket, which can hold the roll of things, plus a halter and lead, bottle of water, bug spray and sun screen. Usually such boxes or baskets have a couple straps run all the way around them and a couple floorboards to hold them in place on the vehicle. We added 4 footman loops under the slat floorboards of cart to run straps thru, around the spares box, to keep straps in place. Footman loops are available from Witmers Coach Shop in Pennsylvania. Same item you run your breeching straps thru under the shafts.
On the roll construction, your width is determined by the longest tool. In most cases that is the leather punch, hammer or carriage wrench. Then you fit the smaller items in between them. No template because we may buy different brand, which measure differently. I would plan to fit MY SPARES in the roll, to keep them permanently in place. No borrowing from husbands tools. We have been amazed at the many times we needed those tools for something, glad the were ALWAYS there to save us or someone else!
Not sure how you plan to hold items in place, within the roll. I have seen buckle straps, velcro straps, string/cord sewed down to tie around each tool. They all work. Stuff just needs to stay in place when the roll is opened for inspection or to get a tool out. Many have flaps on the sides to fold over tools. Can be leather or fabric. Flaps prevent tool loss should the strap holding tool in place break or comes loose. I like our outer straps going aroind the outside that hold everything closed up.
For fabric, something tough, subdued color, to not show grease or most dirt easily. Canvas duck fabric, in cotton, is what the winter bibs are made of, pretty tough and available in many colors. I would wash and dry it first, get any shrinking done before putting work into it. It is also slightly bendable then!! Ha ha I buy it from Fields Fabrics, you can find them online if there is no outlet near you. But it can probably be found other places too.
A suggestion if you have synthetic harness, is carrying a spare rein and spare trace. It is truly difficult, up to impossible, to punch holes in most of the synthetics with a hand punch out “on the trail”.
