Not sure what country you are in, but HVCcycle and B&H have covers in the US, PitReplica is in Thailand and I've had good luck with them, and in the UK is P&P (the web site is motorbikeseats.com) who a few of the Kettle Club folks like. If you want an actual repair, there is Cool Retro Bikes in Florida - not cheap but they do get VJMC traffic. They can repair rip and tears in existing covers, re-dye and re-logo.
Ian
If at first you don't succeed, just get a bigger hammer !
The seat is fine except for the tear. Was thinking about possibly taking the seat to a local shop that repairs car seat. Otherwise will probably get a seat cover from one of the sources you mentioned.
Anyone have experience or views on using a car seat repair shop?
BAS (Bike Acquisition Syndrome) - too many bikes but have room for more
I had years in the motor trade, which involved many many upholstery repairs during that time. We also now produce our own cafe race seats and upholstery pads....which are made by the same guy that did my auto repairs back then.
I think the best way to repair the seat, would be to put a whole new front side in the seat cover, which would probably mean a new vertical seam 1/2 way along (under the strap), the other edges would be at the bead, and at the join on the front of the seat, so would be pretty undetectable. A good upholsterer will be able to do that neatly enough.