Update: I placed a call to Petsmart's corporate office to see if they could tell me who makes the Top Fin labeled tanks for them. The person I spoke to said that they couldn't divulge that information out of concern for losing sales to other vendors. I also placed a call to Aqueon with the same question and the young lady I spoke with said that she believed the Top Fin branded tanks were made by Marineland.
After doing some more investigating this is what I found out. I looked at the 65 gallon Aqueon tank I had and in the corner of the bottom glass panel is a laser etched stamping with the ratings of the glass, type of glass and Aqueon's initials AGA , All-Glass Aquarium Company.
I went back to the store to look at the 75 gallon tank and there was 3 newly arrived units sitting on a pallet. They were all wrapped in a plain brown cardboard wrapper. On the inside of the wrapper was the printing for an Aqueon tank. In the tanks themselves was some promotional samples of Aqueon products. The include light fixture also had a manufactures label from All-Glass Aquarium Company affixed to it.
When I looked at the bottom of the tanks they had the same laser etching as the 65 gallon unit did. I would have to say that these 75 gallon tanks are indeed Aqueon made. I briefly looked at some of the other tanks with the Top Fin label and they also seemed to be made by Aqueon as well. An inspection for the laser etching would indicate the manufacturer.
I did end up making the switch to the 75 gallon tank. I returned the 65g unit and its stand. Now I need to start planning for a stand for the 75.