You probably stuck with the Quick link attachments system. Probably only made by MTD (or Maybe AYP??) I think which brand several brand names. Roybi just being one of the same just different label. Was you old model a two stroke or 4 stroke? I have 4 stroke that's 12 years old and still starts on the second pull cold.

I had a 2 stroke Ryobi with the trimmer plus attachments. It worked well for all those years and was the one piece of equipment I never took care of. I think I may pick up a Husqvarna today and give that a shot.