I just made one with two precision flat screw drivers and a drilled piece of wood. Like the tool above but a stick of wood instead of the two horizontal rods.
Another plug for the S.K. Grimes wrench. But mine did not come in a wooden box. It’s expensive but a fine tool. When buying these wrenches it’s no different than buying any other tool, it simply comes down to how much value you place it fine tools. I have the square Linos wrench and it works and is more portable. But for precision, strength and versatility wrenches like the S.K. Grimes wrench are better tools.
I use one from Edmund Optics, Barrington, N.J.
It has replaceable and different tips and it works fine,
Perfection is a moving target.
The S.K. Grimes wrenches work great. I purchased both of them because when you weigh the price of a messed up shutter or lens as a result of a poor wrench job, well IMHO they are worth the price.
I got this one at ebay for 30.00 with shipping
Whats in back of you is the past and whats in front of you is the future now in the middle you have choices to make for yourself:
I bought the rodenstock and then the toyo version unfortunately neither work with my wood (wisner) #0 lensboard. I guess I'll have to try the caliper style wrench instead. I have been trying to save every ounce and I thought the caliper style would weigh a little more but the lensboard is recessed and the flat wrenches can't get passed the ridge.
Perhaps this info may be useful to other first time wisner owners.