Need one of these emblems for a 1980 Toronado, 5-1/4" long by 7/8" tall.

 

The emblem you describe would be GM p/n 555735 stick-on emblem with the solid backing of the "m". Toro used these on the front fenders and other cars used them on the trunklids. These should not be confused with the 1985-up trunk emblems used on the Cutlass, et al, and had open spaces in the legs of the "m" and wasn't as embossed as the 76-84 version as the only difference.

I happen to have an NOS GM pair of these.

If you only want one, it's $40.00 shipped in the U.S. (PM me for details on how you can save $10 on one)

If you buy the pair, it's $70 for the pair shipped in the U.S. (PM me for details on how to save $15 on both)

Cheapest on ebay is $46 for one that I've seen.