One thing I've not addressed in some time is accuracy of dimensions that you see on the website from various makers. Upholstery is still a hand-made item, and they will vary - do not rely on the published specs if you are seeking accurate measurements. This is addressed in most every maker's price book, the below is one from Hancock and Moore:

"DIMENSIONS: The dimensions we display in our catalogs are approximate. Therefore, because our furniture is hand crafted, these dimensions can vary up to two inches. Please do not assume that a style will always have the exact measurements shown. If a style you have chosen needs to git a limited space or has specific needs, please call the factory to insure a proper fit. We continually make modifications to the dimensions to improve the overall look and comfort."

If you require a specific dimension to be accurate, its critical that you inform your dealer at the time they write the order. For example, if a sofa is 89" long (published) and it absolutely cannot be 90" for your application, the dealer can write on the order "Must not exceed the maximum published length". And that will flag a piece in the production notes and they will then work to make sure its no longer than 89".