Similar to HP 46 ??

[Katie Wasserman]

The HP-81 has the SUBTOTAL functions you describe and was in the exact same case as the HP-46 but had financial functions, no trig functions.

If you're pretty sure about the printer mechanism it could have been a non-HP machine as the mechanism in the HP-46/81 was made by Seiko and used in some other calculators. The Compucorp 325, for example, uses the same printer and is about the right size and color as you describe. It has an optional, external tape drive and was programmable, it used a Panaplex display like the 9815.

Did the printer make a lot of noise? Even when not printing? (This would indicate the Seiko printer)

Another possibility (LED display, similar color/size, no tape drive): TI SR-60

And this monster machine from HP (bubble LED display x 3, much larger, no tape drive): HP-9810