I would say it is possible but maybe difficult to reveal antigens since some (probably most) of antigens don't like gluteraldehyde fixation. For example, Dopamine receptors (D1, D2), etc. In this cases, people often use acrolein as an alternative.
However, I have read some literatures using antigen retrieval technique to increase staining intensity with gluteraldehyde fixed, Epon embedded ultrathin sections. You may want to search PubMed for more information.
The chances of getting positive results are low, but worth to try if it is critical data you need.