I haven't heard anything about a 2 month window, although 12 months might be a bit far back. However, I'm sure if the expenses were genuine business expenses, and you can prove this, then you might have a good case.
It might be worth calling Revenue just to get clarification on your specific situation.
instead of claiming the Vat on light and heat business etc on the VAT return and then claiming the amounts ex VAT from the business ,can you just claim the full amount from the business profits ?