Sounds like good advice - I definitely have some imperfections in the grooves too.
And was it those ebay seals you used successfully after your attention to the corrosion etc. on the caliper?
Following some encouragement from Gemini (AI) I contacted a UK Bearings and Seals supplier - they can do the exact seal for me but 4x the price of this ebay seller and minimum purchase of 100 units!