Old school for chest is push up, every kind you can think of, one arm, diamond, wide hands, regular, military. For back, pull ups, all varieties, wide grip, close grip, hand forward and reverse. If you have no place to do pull ups get a resistance band and attach it to a high point and pull on it in the same way, wide, close front grip back so on. This is what I did when I was traveling thru Asia last year (got it from P90X workout program). With abs variety is also the key, planks are awesome because they use ab muscles not used in a crunch or other typical ab exercises.
A long time ago I had a total gym at that point it was based on resistance, I am not sure if it is the same now. You will get a great workout for arms with a great set of dumbells, where you control the weight better and it is a free weight so you are responsible for the whole motion. This also helps because in order to do curls (all kinds) properly you have to use your core (abs!). For bench just make sure your doing varied inclines/declines maybe 4 types. For bulk 8 reps each set.
And of course there is always the eating side of things. Your ab muscles could be buried by a small layer of fat or not popping out because of your current diet? Cardio always works like suggested above.
Just a few ideas,
Good luck!
Myles