Nikon D80 - creates new folder, starts numbering all over

Question

My D80 died with a locked-up mirror (tried the various solutions on the web to no avail). Since I was happy with this camera and had various accessories I'd just as soon not abandon, I found a very gently used D80 on eBay for less that the price of walking into a repair shop. There's one annoying issue - my SD card has a folder - 100PRIME - that I've been using for years. The new camera insists on creating a new folder 301PRIME for new photos, and starting numbering all over again. (Note that the folder selection menu option only operates on the five letters, not the number prefix.) After trying various things I thought, OK, you win, and moved the pictures from 100PRIME to 301PRIME. Now the camera insists on creating folder 302PRIME. I think the issue might have something to do with numbering - the new photos have lower numbers than the ones in the folder, so it's insisting on a new folder. Is there a way to coerce the camera to pick up numbering where the old one left off?

It's not like it's the end of the world, but just a little annoying.

Answer 1

This from the D5500 manual, I would guess the D80 is displaying similar (if not identical) behaviour, though might be in a slightly different place in the Menu structure.

When a photograph is taken, the camera names the file by adding one to the last file number used. This option controls whether file numbering continues from the last number used when a new folder is created, the memory card is formatted, or a new memory card is inserted in the camera.

On
When a new folder is created, the memory card formatted, or a new memory card inserted in the camera, file numbering continues from the last number used or from the largest file number in the current folder, whichever is higher. If a photograph is taken when the current folder contains a photograph numbered 9999, a new folder will be created automatically and file numbering will begin again from 0001.

Off
File numbering is reset to 0001 when a new folder is created, the memory card is formatted, or a new memory card is inserted in the camera. Note that a new folder is created automatically if a photograph is taken when the current folder contains 999 photographs.

Reset
As for On, except that the next photograph taken is assigned a file number by adding one to the largest file number in the current folder. If the folder is empty, file numbering is reset to 0001.