AOA!

Why don't you give a try to Mercantile law by an indian author "M.C KUCHHEL" (name pronounced exactly in the same way as an urdu word which means CRUSHING)! Its a comprehensive book on the subject with small page-size for easy reading and its pirated-edition is available for about Rs. 70/- at Prince Book Depot & Ilmi Book Centre (Urdu Bazar, LHR) and also at Waheed Book Depot (adjacent to ICMA Building, Lahore).

I recommend this book because it has lots and lots of appropriate ILLUSTRATIONS (small case-studies) and even larger-original case-studies!
Furthermore, as u will see (when u'll purchase it) that CHEEMA's M-Law and LUQMAN BAIG's M-Law are mere reproduction and editing of same matter from M.C Kucchel (which is considered as a master-piece). The reality is, that they both have COPIED from M.C Kuchhel and then have improved the understandability of the text with easy non-legal language and attractive presentation (with headings etc.). But the fact remains that M.C Kuchhel still contains 40% more in-depth material than the other two books & with proper legal language and hence, is my CHOICE #1.

Should you have any further query concerning it, don't hesitate to ask me!

take care!