I can't say if one of Lakeman's rifles has survived.   Of possible relative interest the "British Soldier's Firearm" has some info on the War Dept's version (Pages 42 - 44) also with a pic of the sealed pattern, lock plate dated 1854. I'm not sure how close this is, date wise, to Lakeman's order?  Regards, Adrian.

I am interested and are busy with a long term project on the Cape Gun. There must be links to the
1820's  flintlock  double barrelled smooth bore carbine issued to the Cape Mounted Rifles as well as the 1850's double barrelled rifled carbines.
 
These carbines in South Africa seem to all be muzzleloaders.
 
This is what I have received from a collector in  
Johannesburg:
 
"The pattern 1851 double rifled carbine was originally produced for the 12th Lancers. It is believed that about 350 were manufactured. They were received by the    
 
     Lancers in 1852  while stationed in the Cape and handed over to the CMR when the Lancers were transferred to India in 1854. This particular rifle probably never       reached the CMR. It came from Basutoland and circumstantial evidence strongly suggests that it was captured from the Lancers at the battle of Berea in  
 
     December, 1852 when they suffered severe casualties at the hands of Moshesh.
 
 
 
4)       The Jacob Rifle was manufactured in England over the period about 1858 � 1861. These were originally designed by General Jacob for his own regiment, the Scinde Irregular Horse, but due to his sudden death were, so far as known, never issued in India. The makers, Swinburn & Son, were left holding an expensive baby and probably sold their stock on the commercial market to recover their investment. Hence their appearance in South Africa. I unfortunately do not know the circumstances of  their arrival in South Africa but I guess the date would be in the early to mid 1860s. The Jacobs carbine fits a bayonet "
 
I would say that the double rifles that Sir Stephen
purchased were not on the Minie principle but muzzleloaders.
 
Regards
Mark Anderson
Cape Town