As a field service / workshop supervisor I know that we don't always have the information we need to complete a job. I think you done the right thing getting the information and looking after your customer. Your boss should look at the reasons why you did not have access to the information you required in the first place and as a company president he should be asking questions of his managers as to why they have not supplied the relevant information to enable you to work safely and informed on the job they have dispatched to you. Well done to you for forward thinking.