Hi Doc
It might be a good idea to think about the 4 inch rule as the 70 year old man may not live there forever. Even here the banks do expect railings to be to code if they are loaning money to the buyer. This could be done on the elk design with smaller work to fill in the larger openings. Or it could be done in the other design mentioned pretty easily and certainly you could do it in the traditional design you were thinking of maybe doing, that is one of the nice things about scrolls. Ballisters are also pretty easy to put closer than 4 inches to each other, if they are made of small rod it makes the railing less obtrusive than a wood railing would be and it sounds like you have plenty of small stock to work with and since the frame is made you are really in the more enjoyable aspect of the job now.
I hope you have a good time doing this job.
