.303 pistol???

Had a fellow who immigrated here from S.Africa(Pretoria) back when "the castle started to crumble" as he puts it,show me some guns he brought w/ him today. Quite an eclectic bunch of kit,one was an old but neat Pryse patent .460 Eley revolver with a cool set of pinch levers that open it,a NICE WW1 era mk6 Webley,an OVS marked Mauser carbine w/saddle ring belonging to his Boer g.grand dad,an m-1 carbine from military surplus,and what I fathom to guess is a Boer built Howdah,a crude side by side 12" barrel pistol,in .303.Here's the kicker,one barrel's rifling goes left,the other's twists right! One smooth Metford and the other sharp smokeless Enfield rifling. Welded neatly together. After a brief inspection he dared me to do the unthinkable,shoot it! We took a couple 1944 dated Royal Labs marked MkVIIs and dropped them down the chambers,flipped the heavy barrels closed,cocked one hammer and pulled the front trigger,BOOM,his hand/face was still intact. Handed it to me,cocked the other crudely made hammer,BOOM,more blasted noise! What a rush,nearly leapt outta my trembling hands! Neither bullet hit the broad side of a barn door! Both cases pulled free with the usual Enfield chamber bulge,no splits. Not bad for a home made frame holding 2 different era Enfield barrel stubbs welded together! I'll try to take pics of the thing soon though. Built in the early 30s he says,for safari protection on the savanna. This fellow served in the British Army in the 50s,met him at our local range,it was my pristine 1917 RSF marked Enfield that opened him up. A shame to hear of the recent troubles from his birth-land though. He'll make a fine American,to be sure....I wonder how he got all those guns past customs?