Some of us do not have or have liitle personal payments coming into our Paypal business account,if you do,you should be able to find it in your checkbook or other personal record. such as your Paypal personal account which should be used to accept personal payments unrelated to business.
also your sales ledger should be the ultimate recordkeeping tool for all sales,returns,shipping received,cost of good sold,postage for shipping,insurance ,venue fees,paypal fees and sales tax etc.
This is what IRS wants to see,month by month compared to the 1099 summary by month,ideally it would be kept on computer or disk ,but some of us prefer to do this manually on a spiral notebook,it saves time and you can carry it with you anywhere,in bed or in bathroom?
(the computerised records could be altered and hard to spot,but a manually recorded ledger on paper,it would be hard to alter on large scale ,IRS does study the condition and alteration signs of any papper documents )
The 1099 should agree with your sales ledger,+/- a small difference.
Your sales ledger also allow you to record miscellaneous information such as the country you shipped to, shipper used ,if USPS priority,then insurance included up to 50,100,$200.
There are also data you cant get from 1099s which you need for tax reporting but you can find it in your sales leger,the venue fees-store fee,final value fee of items sold,if you retrieve it from the venue providers.
sales tax is one item which some of us neglect to report,I dont see it in Paypal annual summary .
