This went along just fine until about three years ago, when I discovered the birth/baptismal records for the second group and learned that their father was one Johann Georg Bentz and that his sons were (in order): Lewis, Jacob, Adam (yep, the "unattached" fellow assigned the letter D) - plus some others who apparently did not come to America or died as children.
What to do? Start renumbering about one-half of those in my file?
I decided to do leave things as they are for several reasons.
First, after more than 15 years I was pretty used to the the numbers I originally assigned and it took only a glance at the ID number of an individual for me to know which family I was dealing with. Secondly, I have come to feel that while the Modern Henry System is extremely well suited to recordkeeping, when it comes to publishing, I prefer using the more traditional numbering systems, such as the Record or the Register System.
Thus, renumbering served no real purpose and likely would only confuse me about which family I was dealing with.
Adding to the decision not to renumber is the fact that my back-up paper is filed using the same Modern Henry Numbering System. I started with files numbered, for example, 1 through D (there are actually more). As the contents of file 1 grew, I separated it into files labeled 11, 12, 13, etc. As file 11 grew, it was subdivided into 111, 112, etc. Note that these are arranged in the same manner as would be accomplished by an ASCII sort - all files begining with the number 1 are arranged ahead of all files beginning with 2, etc.
So, renumbering the individuals would also mean renumbering the files.
Here are some points to keep in mind if you use the Modern Henry System:
1. It is an excellent tool for allowing quick identification of individuals. The Henry number tells you (a) which progenitor (first number of ID), which generation (the number of digits in the ID), the ID numbers of previous generations in that line (lop of the last digit to get the individual's father's name, etc.) and the person's birth order within the family (215 is the 5th child).
2. The Henry system is quite satisfactory for exchange data with other researchers. It is so intuitive that even those with no genealogy experience quickly recognize the methodology. I have sent printouts with Henry numbers intact - and with no explanation - to relatives and others and received back additions with the correct Henry numbers assigned.
3. Modern Henry numbers adhere to normal ASCII sorts. This means that a database indexed on the Henry ID arranges individuals in family order. Thus you can search your database on a given name, select a likely candidate, then switch to the ID index and view this person in the context of his/her family.
4. The system usually require less renumbering upon discovery of a new family member - the renumbering is usually confined to that one family, as contrasted with, say, the Record System, where discovery of a new child in the progenitor's family requires that almost every individual be renumbered. The exception here, of course, is the one I described earlier - the discovery of an earlier progenitor.
5. The Henry System is a system for use with a _descendant_ database. While many have tried to adapt it to be used as both an ancestor and descendant database, these systems quickly can become complicated and even contradictory within themselves. (The Ahnentafel System is the clear choice for ancestor databases.)
6. When publishing, a better choice is to use the Record or Register systems, the most widely accepted in the field of genealogy. Warning: If you try to use the Record or Register system as a recordkeeping system or start numbering individuals before you are ready to publish, you will be drived nuts by the constant changes. (Which is why programs that produce printouts in this format assign the Record/Register number "on the fly" during printing.)
Summary: The Modern Henry System is an excellent recordkeeping tool. It is less well suited for publication than the more-accepted Record or Register systems.
For those interested in more detail on number systems, my article "Numbering Systems In Genealogy," is widely available on the WWW. Search for "Numbering" plus "genealogy" and you'll get many hits. Or you can visit my website at Richard Pence
There is a link on that page to a page with links to that article and others I have written over the years.