Is there a way of getting a Mac’s icon given its model number?

1. Mac App Store safe

Manually map model identifier to icon name and then use e.g

[[NSWorkspace sharedWorkspace] iconForFileType:@"com.apple.macbookair"];

or

 [NSImage imageNamed:NSImageNameComputer]

If you need higher resolution than imageNamed provides use

  OSType code = UTGetOSTypeFromString((CFStringRef)CFSTR("root"));
  NSImage *computer = [[NSWorkspace sharedWorkspace] iconForFileType:NSFileTypeForHFSTypeCode(code)];

where “root” string is from IconsCore.h header file (kComputer).

Copy this plist to get the identifiers (do not access it from app sandbox)

/System/Library/PrivateFrameworks/ServerInformation.framework/Versions/A/Resources/English.lproj/SIMachineAttributes.plist

2. Mac App Store unsafe

Link Private Framework SPSupport.Framework with your binary
Add FrameWork Search path variable

$(SYSTEM_LIBRARY_DIR)/PrivateFrameworks

Add following interface into your project

#import <Cocoa/Cocoa.h>

@interface SPDocument : NSDocument

- (NSImage *)modelIcon;
- (id)computerName;
- (id)serialNumber;
- (id)modelName;

@end

Call in your code:

  SPDocument *document = [[SPDocument alloc] init];
  NSImage *icon = [document modelIcon];

3. Hardest way

Figure out CoreFoundation dance with this private function (this code is illustration, find correct types, number of params and release properly)

  output = _LSCreateDeviceTypeIdentifierWithModelCode((CFStringRef)@"MacBookPro6,2");
  NSImage *image = [[NSWorkspace sharedWorkspace] iconForFileType: output];

EDIT:
I just realized that you need option number 1,3 (icon for given model). GL fighting this.

EDIT2
Method 3 added. Changed the order and added under number 1.

EDIT3
New UTIs for the colored version
com.apple.macbook-retina-silver
com.apple.device-model-code
MacBook8,1@ECOLOR=225,225,223

com.apple.macbook-retina-gold
com.apple.device-model-code
MacBook8,1@ECOLOR=235,215,191

com.apple.macbook-retina-space-gray
com.apple.device-model-code
MacBook8,1@ECOLOR=155,158,159
MacBook8,1@ECOLOR=157,157,160

NSImage *image =[[NSWorkspace sharedWorkspace] iconForFileType:@”com.apple.macbook-retina-gold”];

How to get model number/identifier (sysctl hw.model was replaced by system_profiler)?

NSPipe *outputPipe = [NSPipe pipe];
NSTask *task = [[NSTask alloc] init];
[task setLaunchPath:@"/usr/sbin/system_profiler"];
[task setArguments:@[@"SPHardwareDataType"]];
[task setStandardOutput:outputPipe];
[task launch];
[task waitUntilExit];
NSData *outputData = [[outputPipe fileHandleForReading] readDataToEndOfFile];
NSString *hardware = [[NSString alloc] initWithData:outputData encoding:NSUTF8StringEncoding];

And parse Model identifier or your propertylistserialization