Install the Marshall 1960a White Piping
After some hard work, and heavy cement fumes, you should be ready for the piping. I purchased 11 feet of this manufactured by Marshall. It simply staples in from behind the front lip. Staple all the way around, and create a single seam in one of the bottom corners.
Start in one corner, and staple every half inch or so all the way around 
Staple more frequently in the corner to get a good bend 
Continue all the way around until your piping is complete
Wire the Speakers
I didn’t take pictures of this part since everyone’s wiring setup might be different. There are different methods based on the type of input jack(s) you choose, but the methods are easily found on the web. One thing that makes assembly easier is using the slip on speaker connectors so that you can wire everything in the cabinet, then as you put the back on, just slip the two or four connectors on their posts and close her up.
I’m assuming you’ve wired your speakers in the frame they sit in currently. Now we go ahead and slide that frame in the back of the cabinet, and flush with the front lip and white piping you just installed. At this point, I added a 1×1 strip behind each panel as snug as I could get it to keep the speaker panel in place permanently. Go ahead and install your handles now, as they should slide in the holes and screw in easily.
Finishing Touches on the DIY Marshall 1960a
Next, connect your speaker wiring to your speaker jack, and screw on the back panel. I used stainless screws and grommets to replicate the look that Marshall uses. After the back plate is on, turn the cabinet over and screw in your casters or wheels, as well as the corner brackets. Turn her back over, glue the 11″ Marshall logo on the speaker mesh for the final touch. And, now you have all the information you need for how to build a Marshall speaker cabinet.
Double screws in each corner to prevent rattles 
Closeup of the amp caster and corner piece 
Amp casters attached to each corner for easy transport 
Screw the stainless screws all the way around the back panel 
Finished product live and in action!
