Nyet helped me out with referencing the bootrom in me7sum saying before the first // is a good starting point...  I had also read you can check the beginning of the hex.  Of course ill be backing up all of these before i start flashing different files but would like to know if there is anymore insight into the EPK reference and or how far down in the hex you should expect the computers to be the same.  I have a lot of 1.8t projects I'm helping with and possibly some 2.7s so for me just getting well defined .bins makes a world of difference. 

example...

My dads 2002 TT 180hp. 

 EPK         : '40/1/ME7.5/5/4019.20//24B/Dst04o/110401//'
 Part Number : '8N0906018AL '
 Engine ID   : '1.8L R4/5VT     '
 SW Version  : '0004'
 HW Number   : '0261207419'
 SW Number   : '1037362515'

vs

another TT.bin that is well defined

 EPK         : '40/1/ME7.5/5/4019.00//24b/Dst01o/210201//'
 Part Number : '8N0906018AQ '
 Engine ID   : '1.8L R4/5VT     '
 SW Version  : '0001'
 HW Number   : '0261207416'
 SW Number   : '1037360843'

Notice difference starting in the EPK 4019.20 vs 4019.00

but when in tunerpro and comparing the files and maps side by side they are EXTREMELY similar.  only changes are in kfmirl engine load, and throttle axis that I've found so far. 

also in HEX
 the first difference is the above reference 4019.2 vs 4019.00  at the 00010010 mark...

sorry guys for asking this question twice but i thought it could be used in the flashing section and help me and hopefully others fully understand crossflashability.