Want to drill & fit Crud Catcher riveted bosses to u/s of down tube - who can do - any ideas?
Use the elastic band thingy they come with?
this may noy be as straight forward as it seems - depending on the tubes used to build your frame, the wall thickness may be too thin due to the butting/tapering of the inner wall.
That said it is a fairly straight forward task for a frame builder to perform Ellis Briggs at Shipley do it for app. £15
[url= http://www.ellisbriggscycles.co.uk/renovations.php ]ELLIS BRIGGS[/url]
whereas Bob Jacksons would charge double that
You have been given advice on this today already,it's a bad idea but fxxk your frame up if you want to
It's a good idea if done by a frame builder properly. You will probably want a respray after too.
My advice.
Don't bother unless you want to drop over £100 to get it done properly.
Buy my Pace RC305 as it's already got crud catcher bosses on it 😉
Use the force.
[img] 
[/img]
I'm failing to see what the problem is with the rubber loop you get with it? Never, ever had a problem with it on any bike, ever. Or are you trying to over-engineer a solution?