the 1.5s may be available again, it no longer states 'Please contact us', it's now showing 'Add to Cart' !...I got mine in 2 days via USPS!...that's a cross-country trip to me in D.C....I was amazed...you may want to call 'em...I'll be drillin' away this rainy weekend 
http://www.mcgillswarehouse.com/ItemDetails.aspx?ItemID=154120005&IN=SILVERBRAZEDDRILLBIT,14"LX1.5"W,with5segments.
Wouldn't you know it.. I just bought one on Ebay, paid a little more, getting rid of cat..PRICELESS>>>>Greg
Item number: 160286942753
This is ONE 1.5" “BRAND NEW - PROFESSIONAL DRY” Core bit that is built for jobs that have no water feed and jobs where water isn’t necessary. Body air vents on the core bit allows fast clean drilling and extraction of filled substances. Perfect for Brick, Block, Flagstone, Concrete Pavers,Concrete Pipe,Quarry Stone,Roots,Slate,Tarmac,Terra Cotta, Roof Tile, Blue Stone, Sand Stone,Clay Pavers, and other hard materials. Not recommended for cutting into mass rebar due to the lack of water for heat dissipation. Use on angle grinder or core rig. It features a full 10mm segment height.
It has a 5/8-11 Thread arbor.
The OAL (Overall Length) is 10” long. It is a DRY cutting bit. Item (Core Bit) is shipped to your front door BRAND NEW in the manufactures box.