After doing some research here is what I came up with:
There's an outfit in the UK that makes line-contact replacement styli for Grado carts. Lotsa stuff on the Vinyl Engine about this, supposedly a huge upgrade for any Grado with a user-replaceable stylus.
I think the company is Expert Stylus; it doesn't have a website but can be contacted by email. The replacement styli weren't outrageously expensive last time I read anything about them, more than a regular Grado but not a whole lot more.
I did a search and came up with this email address: info@expertstylus.co.uk
Otherwise, IMHO, you’re better off getting a new cartridge.
Affordable & recomended by 1200 owners:
Audio Technica AT95e $50
Nagaoka MP 100 $72
Shure M97XE $89 (it can pay to shop around for this one, often priced less elsewhere)
Nagaoka MP 110 $99
Ortofon 2M Red $99
Denon DL-110 $139 (output may be too low for some phono preamps)
Shure M97XE $55
Audio-Technica 120E $70
Grado Prestige Green $80
Grado Prestige Red $110
Grado Prestige Blue $110
The best prices can usually be found at J&R or LP Gear.