I would not recommend your husband going through his taxes with an HMRC official. He may end up paying too much tax or too little and HMRC will blame him for any errors even if one of their staff helped him with it.
Given what you have told me, especially the fact that he appears to have worked abroad, I would recommend that you find as much information and paperwork as you can relating to his income and finances and look for a local accountant who has good tax knowledge. If a friend or business contact can recommend one, all the better. You'd be surprised how many accountants there are who know little about tax other than completing a tax return. A good accountant or tax adviser can take away much of the stress of this type of situation.
As he appears to have worked on month of, month off basis, I doubt that your husband will qualify as being non-UK resident for that period but its worth having somebody look at that.
At some stage, your husband will probably be issued with a corporation tax return and an annual return for the limited company so an accountant can deal with those for you.
The sooner you can get on top of this and show HMRC that you are doing so, the better, as there could be tax related penalties in addition to the late tax return penalties already charged. You can read about the penalty regime here
I hope this helps but let me know if you have any further questions.