Nice looking car, great job. The best method for adjusting the play out of the steering box is from under the steering box. The green bible makes if very complicated. I have a 51 and have successfully taken nearly all the play from mine. I have a document written by one of the forum members that works like a charm. I don't know how to attach the document so I will try to cut and paste it here.
Remove slop from steering wheel:
From Dan Hayes – on shoebox central forum
If you follow the manual it is going to lead you on a long drawn out process that can seem confusing and in my opinion makes things more complicated than they really need to be. 1st and foremost you need to determine where the slop in your steering is coming from. Obviously if your steering components or idler arm has slop, you need to address those issues first. So assuming all other components are tight and you have determined all (or at least most) of the slop is in the box (by having a helper wiggle the wheel while you watch underneath) and also assuming your box is in good condition with no broken components and is suffering from only normal wear due to 65 ish years of use. Be sure to follow the instructions to a T and dont take short cuts or skip steps and you should find yourself pleased with the results.
* Loosen the jamb nut on top of the steering box several turns and back off the flat blade screw (pin) a full turn.
* Get the car safely up in the air (A lift is ideal but jack stands under the frame will do the job)
* Loosen 3 of the 4 bolts on the bottom of the box a couple rounds.
* Mark 1 continuous reference line on the bottom of the box across the main housing and across the adjustable flange (the part that is clamped down by the bolts you just loosened in the previous step). I clean a spot off with brake cleaner and use a thin paint marker, anything will work just make sure you have a clear line marked for reference before you begin adjusting.
* Loosen the 4th bolt but only enough to allow the bottom of the housing to move.
* Carefully tap the bottom housing clockwise (laying under the car looking up at it). Only move it about a 1/16" at a time. This is where you dont want to get carried away, just watch your reference line and only move it a hair (An inch = a mile).
* Tighten 2 bolts just to hold it for now.
* Check the steering wheel to see if the slop is better or gone.
* If there is still slop, loosen bolts and give it another tap. You will likely have to do this several times to get the slop out.
* When you feel the play has been removed from the box, tighten all 4 bolts on the bottom and let the car down.
* Carefully run in the flat blade screw on top but only until you feel it touch the worm gear. DO NOT overtighten, (all your doing is making contact). Tighten the jam nut.
* Take it for a drive, if it still feels a little loose, repeat process and bump it another hair.
If the steering wheel feels catchy and tight and doesnt want to spin back when you are coming out of a turn, you have went too far and the box is adjusted too tight. In this case, repeat the process but this time just slightly bump the flange counter-clockwise to loosen it up a hair. (Remember an inch = a mile).
Hope this helps, I look forward to hearing your results.