Okay, there is definitely an error message coming up in the log. I only selected a few messages from 2008 to restore. I selected just one of the error log messages I received (essentially one for each email it tried to restore). Thanks for all your help. As an aside, if it helps you to respond, I've just started a computer science degree, so I'm starting to feel my way around this stuff, but have a good cursory understanding. Not to say that your directions aren't just succinct and perfectly laid out!
9/23/14 7:16:07.421 PM Mail[3178]: *** Assertion failure in -[DateCell _initDateFormatter], /SourceCache/Mail/Mail-1878.6/Mail/Mail/MessageList/RowUI/DateCell.m:475
DateCell requires its date formatter to have 10.4 behavior
(
0 MailCore 0x00007fff89ad08bc -[MCAssertionHandler _handleFailureWithPreamble:description:arguments:] + 141
1 MailCore 0x00007fff89ad072d -[MCAssertionHandler handleFailureInMethod:object:file:lineNumber:description:] + 215
2 Mail 0x0000000100f1fe0f Mail + 97807
3 Mail 0x000000010104b51b Mail + 1324315
4 AppKit 0x00007fff925bd9f0 -[NSTextFieldCell init] + 31
5 Mail 0x00000001010fdc23 Mail + 2055203
6 Mail 0x00000001010fe096 Mail + 2056342
7 Foundation 0x00007fff8c017dbe -[NSObject(NSKeyValueCoding) setValue:forKey:] + 389
8 AppKit 0x00007fff925e2f0d -[NSObjectParameterBinder _updateObject:observedController:observedKeyPath:context:] + 1298
9 AppKit 0x00007fff925d9f08 -[NSObject(NSKeyValueBindingCreation) bind:toObject:withKeyPath:options:] + 652
10 Mail 0x00000001010f2e21 Mail + 2010657
11 Mail 0x00000001010f3cba Mail + 2014394
12 Mail 0x0000000101139bfb Mail + 2300923
13 Mail 0x000000010113aaff Mail + 2304767
14 Mail 0x000000010113af62 Mail + 2305890
15 Foundation 0x00007fff8c035784 __NSFireTimer + 96
16 CoreFoundation 0x00007fff880973e4 __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__ + 20
17 CoreFoundation 0x00007fff88096f1f __CFRunLoopDoTimer + 1151
18 CoreFoundation 0x00007fff881085aa __CFRunLoopDoTimers + 298
19 CoreFoundation 0x00007fff880526a5 __CFRunLoopRun + 1525
20 CoreFoundation 0x00007fff88051e75 CFRunLoopRunSpecific + 309
21 HIToolbox 0x00007fff8884ba0d RunCurrentEventLoopInMode + 226
22 HIToolbox 0x00007fff8884b7b7 ReceiveNextEventCommon + 479
23 HIToolbox 0x00007fff8884b5bc _BlockUntilNextEventMatchingListInModeWithFilter + 65
24 AppKit 0x00007fff9255124e _DPSNextEvent + 1434
25 AppKit 0x00007fff9255089b -[NSApplication nextEventMatchingMask:untilDate:inMode:dequeue:] + 122
26 AppKit 0x00007fff9254499c -[NSApplication run] + 553
27 AppKit 0x00007fff9252f783 NSApplicationMain + 940
28 libdyld.dylib 0x00007fff86fdd5fd start + 1
)