how long is too long to leave fish in the freezer

As long as the towels were very wet when you put it in, you should be okay to go. I have mntd fish that were wrapped in saran wrap and newspaper(both big NO_NO's) that wer so dried out that they wouldn't even freeze anymore. The fish weresoft to the point of being able to dent the skin about 1/4 inch with your finger. Some of the meat had even pulled away from the skin on the inside. One of these fish which was given to me by a customer still hangs in my shop today.Not all fish are salvageable, depends on the species, but yours should be fine. If you are going to wait a while before you get it mntd., I would suggest opening the bag and just dumping a couple cups of water in then re-bagging. Just let your taxi of choice know what you did and how long it has been.

This is the fish. It is the same fish in my banner above.

There are two ways to do a fish. Actaul skin mounts use the real skin over a foam manikin. These fish are positioned, dried, then painted by the taxi's chosen method. Lots of problems this way-tissue shrinkage in various areas, chance for leftover grease bleeding through the finish(always some meat and grease left after skinning no matter how careful the taxidermist is), a very blotchy skin that must be properly toned prior to painting, and the possibilty of future cracking as the skin expandsand contracts with temp. and humidity changes. These reasons are why we quit skin mntg. fish. The other way that fish are handled is to get a reproduction made. We mold fish as they come into the shop and make a custom reproduction out of fiberglass. Reproduction fish can also be purchased to match length , girth, and weight measurements of your fish. This will be a generic fish close to what you caught, but a custom casting will be an exact replica of your fish. Reproduction fish do not have the disadvantages of the skin mntd. fish mentioned above and have many advantages such as:perfect anatomy that can't be approached in a skin mnt., much easier to deal with for the taxidermist during prepping and painting, and longevity-the fiberglass is temp. and humidity stable. The biggest disadvantage is cost as the time in molding adds to the work needed for the reproduction, but 20, 30, 40 yrs. from now your trophy will look just like day one when you received it from the taxi.