Ed said,
I assume you don't have the oiling holes in the sheaves on your machine, but maybe it's been upgraded, I don't know when those became standard. I'll bet chapmamruss knows, maybe he'll see this.
So I did see Ed's post. My best guess based on information from the early Shopsmith Owner's Manuals is by late 1956 there were oiling holes in the movable sheaves. The 1st, 3rd, 4th and 5th editions of the Manuals don't even mention oiling the sheaves in the Maintenace and Lubrication section. The 2nd edition of the Owner's Manual from July 1954 has the following
MOVABLE SHEAVES - After every 50 hours of running remove the belt guard D2829 and squirt several drops of light machine oil between the sheaves on the idler shaft B2803 and the motor shaft.
At that time there were no oiling holes in the movable sheaves judging by the lubrication description. Beginning with the 6th edition of the manual dated October 1956 and continuing in later editions, there is a more involved description of oiling the sheaves which includes adding oil through the holes in the movable sheaves. This is still the method of oiling the sheaves used today and can be found beginning on page 53 in the Mark V 500 Summary Manual at the link below. This Summary Manual is from here on the Shopsmith website. It also has more information on using a Mark V than those early 32-page manuals included.
https://www.shopsmith.com/getting_started/500_Summary_Manual.pdf
Ron,
As for adding the access hole under the Name Plate the diameter at the top and bottom of the hole needs to be the correct dimension to allow the clip on the back of a "B" Headstock Name Plate to hold it in place. The tabs on the left and right sides of the hole are for the pins on the back of the Name Plate to rest in to keep the Name Plate straight. A hole for the Name Plate could be just as functional without those tabs.
You said about the Speed Control, "The dial is stubborn" which may be caused by the Speed Control Assembly or the lack of lubrication on the movable sheaves or both. This would be a good time to remove the Speed Control from the Headstock casting to check its condition. Doing this with the Headstock opened up will make this easier and you can access the back side of the Speed Control Assembly to slip the Idler Shaft Retaining Loop off the end of the Quadrant. The first thing to remove is the Control Handle Assembly which is held in place be a set screw. That set screw is accessed through the notch in the handle side. This would be a good time to take pictures as you go. The rest of the assembly is removed from the Headstock by removing the 3 screws holding it in place. This is when you slip the Retaining Loop off the end of the Quadrant. Don't remove the gear on the left side of the assembly at this time. It should be left in place unless it has some damage to it. With the assembly out of the Headstock you can examine the gear and teeth on the back side for excessive wear. Here is some good news for you, The Speed Control Assembly and its parts sold today are the same as the ones used in your Mark 5 all those years ago.
As for lubrication use lightweight machine oil like 3 in 1, sewing machine oil or Zoom Spout oil on the movable sheaves of the motor and idler shafts. The Zoom Spout Oiler works great for those hard-to-reach places. Dry lubricants are good for places like the gear and teeth of the Speed Control Assembly or any place needing lubrication that otherwise could attract sawdust. Use the Maintenance instructions found in the Summary Manual linked above but use a few extra drops of oil on the sheaves to begin with to get thing moving well again.
