A beetle engine stolen???
Now there has to be an interesting story to this.....anyway sorry for your loss. Plus if it was the original for the car then a bigger sorry.
In Pindi you have to try out Sultan ja khoon for the VW shops there. In Lahore Bilal Gunj. Plus you can try out the various Beetle specific specialists.
A second hand engine costs anything between Rs 10 and 15 thousand. Depends on the mood of the seller. You might be lucky to get a running bolt on unit otherwise its better to rebuild an engine with doubtful history.
We recently purchased a 1600cc unit from Karachi's Shershah market. It was for KPShiekh, an Isloo based VW nut. Cost him a total of about 18-19 thousand to buy the engine, get a custom crate made, frieght to Isb and transport to his home.
Best of luck!