The issue is even if you find the manufacturer the style may be out of production or a different lot. Meaning the color or tooling or hardware could be off. Is this an upper or lower door? If it is an upper you can always have a fine woodworker make a door with a glass front. For a lower, you can optionally re-tool the inside to be open shelf and baskets.

http://www.kcma.org/consumers/who-made-my-cabinets

It is a thermafoil door (not painted) We want to remove a desk and put in a lower cabinet/pantry but I want it all to match - they can't seem to custom make a thermafoil that will match existing.

There are always creative alternatives to consider before making the expensive plunge.

Don't match. Make an accent of the pantry with a stain...or a color. There is little point to replacing cheap cabinetry with more cheap cabinetry. Best would be to SAVE your money and wait until the resources are greater than "shoestring".

http://www.rekitchen.com/cabinets/reviews/thomasville/

Thermafoil is a laminate pressed to MDF and very water and moisture proof. They clean easily and depending on the grade of the cabinet they are shoddy to very well made. It is manufactured by a number of big names such as Aristocraft and Kraftmaid. You need to check the joins and the hardware - particularly hinges and slides - used in the making of the cabinets to determine the quality.