I managed to complete this by identifying the name of a very well known American writer ( 4 letters ) from those circled. The remaining 5 give a means of transport. By googling the name and the means of transport I found the work ( just putting an extra letter into the three letter word at the end of the instruction will also give you the second word of title ) and the names. Two of those listed by Sunray are right - including the clued one at 31 down, with the other running across answers - and a T needs to be added at the start of another. The one at the start of 42 across is not one of the thematic names. You need to put a letter - part of a surname - in the blank square. The puzzle title tells you what that letter is. 11 across - the definition is classical struggle, 13 across - the definition is in one piece and 27 down the definition is smuggled booze ( as a verb ). The unchecked letter is P.
Alwayspuzzled, I have the paper edition of the crossword and the nine circles don't give what you've said - though I think they were meant to! There's a missing 'i' and an extra 'n'. To me it looks as if row 11 should have had the second circle just one cell along.
Although the online version might have been more accurate, I thought I'd mention this in case it has confused any other solvers.
Googling the (supposed) two words from the nine letters only led me to Charlie the Choo-Choo and for a while I thought this had to be right because there wasn't anything else, even though it didn't make sense.
It was only when I read alwayspuzzled's comment more carefully and added an extra letter to the last word of the instruction that I got on the right track. I've only come across this book before through a Family Guy spoof.