Considerations for starting new books for a company with 5 years of data

SUGGESTED

I've been in the Quickbooks world for a long time and just refamiliarizing myself with Sage. I'm using Sage 50 Local, I hope this is the right discussion forum.

I have a client/company that needs his bookkeeping brought up to date, there's about 5 years worth of data  (Company A) 

Where my question comes in is, he has what was a separate Company B that we are just finishing bringing bookkeeping up to date. (Partnership dissolving in ruins). He will likely bring it in under his existing company,  call it Division B. (he is continuing to provide services on his own)

From what I have been able to tell, Sage only lets you keep 2 years open. 

My preference would be to simultaneously work on keeping Division B current while getting the 2017 - 2022 of Company A brought up to date, but it sounds like that would not be possible...??

If someone could confirm this for me I would really appreciate it, and any helpful suggestions gratefully accepted.

I would also like to better understand how much editing of entries is possible on historical data ...once the period has been rolled forward. Needless to say, no taxes or reports have been filed for either of these businesses.

Is there an article somewhere that goes into detail on this subject?

Again, many thanks

Janice Pickwell