Suggest using ilford pq universal. on tests with this vs hc110 dil a, the pq universal didn't delvelop fog on paper, but the hc-100 did--like very quickly--less than a minute, where the pq didn't do that. It works on film as well. Get yourself a tiny bottle and give it a try-what you want is the developer with the least amount of fog.
Overexposing the film with that much base fog may just make things too thick and give you blown out highlights as well. expose @ 400 or 200 most and develop with the developer which gives least fog. Print accordingly OR, better yet--put it in ferricyanide bleach to cut the fog for easier printing.
Better yet--toss the film and buy new film.