thats not to hard to do:
Just make a 2 track recording
on the first track the number 1 song and on the second track afcourse the 2nd with a little overlap on the end and you do the same thing with the rest of the songs. The overlap should be 0.5 sec. tops 1sec. and you hear no gaps between songs. If don't know what i'm talking about send me a mail to this adress: email@example.com
and i will send you a pic. so you can see what i mean!
good luck, by the way the best software for this is: Magix- music cleaning lab! on this programm you can remaster the whole thing, noise reduction, stereo enchanger, surround sound ect...i use this for quit some years and it is the best software around. Most of the soundboards were recorded in mono and with this software you can create stereo sound and even better create surround sound, wich will be a HUGE improvement soundwise.