My old account, wanting to sell it, want some suggestions as to what I should do with it to make it more appealing, or is there anything these stats would be good for?
99 Herblore is always a big plus for overloads, but the main thing I would be concerned about is dung. You should try for at least 80 before you sell it, you'd probably get more for it then.
I agree on the dung part. I wouldn't put the money into prayer because people can be really cheap here on Sythe and not want to pay a lot for an account, although you are an ex-mod so people may be willing to pay a lot more.
If you were to get it to 99 constitution and 99 attack, as well as dungeoneering, people would want to definitely buy it more. It would be a very good staking account.
As well as the other skills people have said summoning would be a nice addition. If you were to get charms while training attack and strength you could get enough charms for 96 summoning at waterfiends. I would get a chaotic maul before training your combat skills though as it smashes Waterfiends(literally)