Unless you want to pay for an ad in the paper, all you can really do is advertise them on facebook or tweeter. You can't advertise them here, the mods will remove your post if you do.
Can you add any more keywords to your titles? Try and use all the space that's there if you can. Think of specific words that people might search for. You could add 'wrestling' for starters, because someone might search using only that word. If any of the people on the cover are really popular, add their name as well in case someone is just looking for something relating to that fighter.
In the description you could put the names of the fighters featuring on the covers. Some people search the descriptions as well as the titles when they run a search.
I know a friend of mine would have loved those magazines, he lived and breathed WWF. Unfortunately he passed away 12 months ago, so no use there!
Edited to add: The forums you tried to advertise your magazines on, if you only just joined and then posted ads, they would see it as spam. You'd be better of joining some sites and getting to know the other members first, then ask if they mind if you post some ads.
