Dave - My recommendations for handholds follow. You can choose between what I call solid or rope systems. I use the five foot teak rails attached from the bottom of the side overhang (an inch inward). You can use SS screws from the bottom, or have quarter inch inserts put in the teak bottoms (between the loops) and drill a quarter inch hole in the roof and run a quarter inch by 20 SS bolt from underneath into the insert and snugged up, or drill holes from top to bottom of the railing through the roof and use a quarter inch pan head 20 SS bolt with SS washers and nut for securing. In the last system, you need to use a Forester bit to countersink enough to put in a teak plug for a nice, neat appearance on the top of the railing.
I have done both of the last two systems on two different 22' Dorys with complete success. You may wish to use SS railings instead of teak. I have found SS railings to be cold to the touch and in wet weather slippery.
Teak has that good non slip feeling.
Regarding the hand holds for the brow, I have employed two different systems. The first was using four (4) single loop teak rails spaced along the top and near the edge of the brow. This was helpful - far superior to grabbing the brow from the bottom where the overhand is too skimpy. That requires some fiddling to get the bases to follow the contour and bear evenly.
But on my second 22' I decided that I needed the whole enchilada. Remember that I turn 75 this July and lack the balance and agility of many of you youngsters. Don't worry, you will find out in time what I'm talking about.
Anyway, my second dory employed the rope system, and it is utterly superior to the solid hand rail. I decided to run a three quarter inch nylon rope (with a soft lay) around the perimeter How to do that? Get a piece of white oak board 3x2x10 inches. Drill a quarter inch hole (I used five (5) support columns meaning I needed five holes spaced correctly. Using the pre-drilled holes as a guide, use a two inch hole saw and cut out a hole (five times) It is best to clamp the oak board solidly when doing this.
A good drill press is most helpful doing this. Carefully pry out the now round blocks of white oak which all have a nice centered hole.
Place the blocks where you want them to go on your brow (perhaps at the painted edge) scribe where you want to drill a quarter inch hole into the brow. Use the old German carpenter method of measure twice drill once with each hole.
Now take five (5) SS eye bolts (1/4 by 20) three inches long , push the eye bolts down through the oak columns and brow, and snug up with the appropriate washers and nylock nuts. I make neoprene washers to fit under the round oak columns to protect the brow.
Next, take your nice soft nylon rope, thread it through the eyelets and secure both ends. You now have something to instantly grab and easy on the hands. The rope is elevated enough so you can slide your fingers over or under, depending on your situation.
If you want to maintain the teak decor, stain the white oak columns with dark penetrating walnut stain quickly followed by penetrating red oak stain. Rub off the excess, let dry and put on a good spar varnish, etc.
Sorry for this lengthy explanation. No, I don't have pictures to put on the net. Am not that techy yet.
John