1- the problem when you add a Scott number like 11a-1 etc. The stamp does not sort properly, it is placed at the end of the list. It is a bug in the program. I had this same problem, and was able to fix it by going into the main program through MS Access. The way you talk this would be way over your head.
2- I suggest that you add a stamp the normal way and look if the variety is listed (example Scott 11 Gash on the shoulder is listed as 11.27). If your variety is not listed, add the stamp as Scott 11, click on the Additional Information tab at the top of the data entry form and put whatever info you want there.
3- From the main screen go to Tools Menu then choose Preferences, then choose Columns. From the drop down list choose Showing Category. From there you can choose which columns show and in what order.
You cannot duplicate Scott Numbers in DataManager, but you can have multiple listings of the same Scott Number in your collection, that is why I made the above suggestion.
Hope this helps you. Let me know