Suggestion on how to number assets

we want to have two books of our existing assets, one for tax and one for GAAP. The tax register was added last year and now we need to enter the GAAP register. Since we need to renumber the assets for the new register, does anyone have a suggestion on how to handle? the tax register numbering starts with one and goes through 23072, to date (we used the numbering from our former CS system instead of creating a new number sequence. I was thinking of starting the GAAP register with 100000.

It will be the same asset number with two registers attached to two books. Why new number required ? Am I missing something ?