Jerry,
With regard to removing anodizing from your Blackburn rack, this can usually be done quickly, efficiently, and at little cost by taking the item in question into any quality plating shop that actually does anodizing work as they must often perform this very service in preparation for applying a new anodized top coat. Alternatively, I have read many an internet article or posting claiming that one can use oven cleaner to affect the same result. However, I am more than a little hesitant to provide my recommendation in this regard inasmuch as I have never tried it myself as well as the fact that there would appear to be almost as many cautionary notes regarding this methodology as there are internet postings proclaiming its supposed effectiveness.
With respect to rendering the Blackburn rack itself silver instead of black, I offer to you another alternative which I have used personally and which does come with my full recommendation. I most recently ran across this very same conundrum when looking to affix a modern Topeak Explorer tubular rack to my slightly off topic Raleigh "SlopCycle". These racks are currently only available in a more contemporary black finish which I thought would look rather out of place on such a vintage bike. So, after stripping the rack of its existing finish, I chose to repaint it using a specialized and highly durable hammer tone silver that was developed specifically for use in the refinishing of painted wire wheels as found on various makes of classic British sports cars (...and I have used it for that very purpose on many occasions and for many, many years). Not only is said paint durable enough to withstand the rigors or regular use without chipping and peeling (...assuming that it is applied in a thin coating and not some thick, heavy, almost ready to run form), its classic hammer tone finish does not have that cheap "rattle can silver" appearance. In fact, it is a dead match for the original silver paint also used on the head tube of various models of Raleigh bicycles, including my own example. The paint itself is sold worldwide through Moss Motors of Goleta, California and may be ordered either online at MossMotors.com, through their printed catalog, or via their toll free telephone number of 800-667-7872 using the part number of 220-560 where individual 12 ounce spray cans (...enough paint to cover several racks or at least five British automotive wire wheels) are sold for $15.95 USD plus shipping. For those interested in at least a partial view of how this product looks when applied to the aforementioned Topeak rack, you are welcome to peruse the photograph found using this link:
Robert "not a paid endorser - but I could play one on TV" Broderick ...the "Frozen Flatlands" of South Dakota Sioux Falls, USA
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>From: Jerome & Elizabeth Moos <jerrymoos@sbcglobal.net>
>To: loudeeter@aol.com, classicrendezvous@bikelist.org
>Subject: [CR]Removing Annodized Finish
>Date: Tue, 10 Jul 2007 07:23:24 -0700 (PDT)
>
>I have a couple of Blackburn racks anodized black. Never liked the black
>as well as silver, partly because small scratches are more evident on the
>black racks. Anyone know a way of removing the black anodized finish,
>other than sanding it off? If not, anyone had good results respraying
>these black with spraycan paint to cover the scratches?
>
> Regards,
>
> Jerry Moos
> Big Spring, TX