I got burned on Ebay. There is a vendor selling K&N air filters for TR7s and he lists all years 75 thru 80 in the title of his ad. The price was great so I bit. The filter came and it was round and not rectangular. I know some TR7s, California cars, maybe fuel injected ones, and perhaps some early models, take a round filters. But the vast majority take a rectangular filter. There is a chart further in the add that is titled "additional makes/models.." which talks about these cars. The guy did refund my money, but he was near impossible to reach and he would not pay return shipping.
nick
'79 TR7