Seatpost Stem 26.2 to 27.0 mm

I'm building a pre-war track bike replica, gathering parts mostly from eBay. I got my hands on a beautiful NOS Campagnolo Record Aero seatpost, to fit a Dawes frame I was planning to use (26.2mm). After that purchase, I got myself a custom frame that has Cinelli bottom bracket and Campy dropouts, can't decide if it's a real Cinelli Pista or a custom build frame just with the parts, it came repainted w/o any decals. I can't afford not using the Campy seatpost and need a stem that's going to convert 26.2 to 27.0 mm. Turned Google upside down, can't source anything this size. I'd really appreciate any help on this, even a contact that could make me a custom stem would do...

[ulist]
[li]Here are some parts I've collected for my project:

Used Track Frame 54cm - Cinelli BB, Campagnolo dropouts
Used Campagnolo Pista Crankset 151BCD 46t 165mm (50s)
Used Campagnolo Strada Crankset 144BCD 53/44t 175mm
Used Cinelli Milano Pista Stem - Rare stem 25.4mm (50s or 60s)
NOS Campagnolo Record Strada headset
NOS Campagnolo Record 32h QR front hub
NOS Campagnolo Record Aero seatpost 26.2mm
NOS Campagnolo Victory brake set (in case I want to use a front brake)
New Soma Major Taylor dropbars (1930 replica)
New Brooks Swallow saddle - Honey (1938 replica)
New Cerchii Ghisallo 700c 32h Wooden Rims (awaiting queue)
New KMC Inox chain
Need a few more parts...[/li]
[/ulist]

If the difference is 0.8mm - couldn't you use a 'USE' shim that is designed for the same diameter difference? You would not get as much wraparound, but it might be fine / better then homemade..? - sadly only found a plastic one for 25.0 - 25.8 here. Searching intarweb could turn up an alloy one somewhere..
http://www.chainreactioncycles.com/Models.aspx?ModelID=820
CRC has 4 different brands: http://www.chainreactioncycles.com/SearchResults.aspx?BrandID=0&CategoryID=0&Search=seatpost+shim
[EDIT] - Wiggle has more details - apparrently only plastic for the thick ones... http://www.wiggle.co.uk/ProductDetail.aspx?Cat=cycle&ProdID=5110000413&n=USE%20XCR%20Seat%20Post%20Shim
Thats a really drooly component list - nice one!
[EDIT2] - a quick google has located a 27.2 - 28.0 alloy shim that should fit the bill with more wraparound (no slippage!)- yay!
http://www.totalcycling.com/index.php/product/parts_accessories/seatpost_shims/use_shim.html