Mark, The SEM coating you have is the old coating and can be used on hard plastics and some vinyl.
Do not use it on leather, for leather you should use the surecoat waterbased. Its far superior for using on leather and does not peel off or fail. Use it with the crosslinker and get your prep 100% and it will stick for life.
One of my services is leather repair. I see it as a very good additional income. I buy my products from NWSR and Vinyl Pro in USA, A guy called Thad runs the business with his wife Donna.
I met up with them both a few years ago and they really do know their stuff and have a good relationship with SEM.
He sells DVDs which can help guide you if you have not had thorough training. I charge a minimum of £90 for any leather repair in a car and £150 for any repair in someones home or office.
I have repaired dentist chairs, aircraft seats and leather sofas for customers local to me.
I had a customer that had a brand new leather suite delivered and the delivery men scuffed all corners when trying to get it in the house.
I charged £200 and was in and out in less than 2 hours!
I always charge more when working in someones home as the risk for damage is higher and you need to work very cleanly and carefully. Spill a drop of paint on that carpets and

:-
I really enjoy leather and any interior work as the customer is always amazed and the work pays really well IMO. Look up Vinyl pro on the net.