I have had a lot of the Metal Bench ends for my restorations, but I don't recall there being a different hole pattern on the top for attaching the Bench Boards. Some have had some extra holes drilled into them by previous owners for some, unknown to me, reasons. The only difference I know of is early Metal Bench Ends did not have the mounting holes for the Retractable Casters. If you can post pictures of the Bench Ends, I would appreciate seeing the differences. I did have one Metal Bench Ends set that was different than the rest, but it was a non-Magna set made by someone patterned after the OEM set. It used a heavier gauge metal and was about an inch taller.
In the picture below you can see the common pattern for the Carriage Bolts to attach the Bench Boards to the Metal Bench Ends. This one is easier to see with the cut-off Base of this 10E. Normally the Base has a centered bolt hole at the end (see second picture below for the bolt hole position) that goes through a hole in the Metal Bench End. This was true for both the larger Base and the later smaller Base. There is bolt holes in the top of the Metal Bench Ends for the Headrest to attach through. When the smaller Base along with the two Bolt Headrest came out the Bench Boards recommended length went from 60" to 57".
_
.
A normal Base can be seen on the Model 10E below. It also has the four Bolt Headrest.
_
.
The smaller Base with the two Bolt Headrest on a Model 10ER is below.
_
.
The Model 10's above are restorations I have done
Below is an early set of Metal Bench Ends. The one on top has a couple of extra holes that have been drilled into it in line with the Headrest holes. The one on the bottom, half covered, has only the original holes. This early set does not have the Retractable Caster Mounting Holes but did come with the SS Logo Decals.
_
.
The attached PDF below is the instructions for the later 57" long Bench. The earlier instructions specified 60" long 2 x 8 boards.
_
.
I have included a lot of information and the pictures for others who may wonder about these things.
Shopsmith Bench Ends 07-52.pdf
