I've found that the Langka solution works fairly well at removal of old touch up paint, without running the risk of using sandpapers and possibly cutting through clear-color coat.
You can work and rub for a long time without harm, and I have smoothed poor touch up I did on my vehicles that on one, had been applied at least 12 years prior.
Yes, you'll have to rub more, but if you only concentrate on the blob, no harm should come to the surrounding factory applied finish.
Dependent upon how well the touch up was done, you may not need go any further than the Langka Solution, that the Blob will be leveled to your satisfaction.
If not, then I would suggest a follow-up with a paint touch up system such as Dr. Colorchip, as I think this system works a lot easier-better than Langka.
Dr C Chip paint formulations has advantages of ultra quick drying, which one can level excess within a few minute's time, something factory type touch up paint doesn't do. It also stays put when doing touch up on vertical panels without a tendency to run-sag.
The Langka product is available right here, and Dr. C Chip can also be ordered here, and is then dropped shipped direct from the company.
Hope this helps you.
