The original part is TSOP1138.
I have a source for it in Europe, but only professionals can buy there.
There is also replacements available. These are not exactly the same.
Some have different pin-order or even need an extra pull-up resistor to work correctly.
TSOP1738, TSOP2138, SFH56-38, SFH506-38, SFH5110-38
If you can't find it I can buy one for you and ship it to you if you like.
I guess it won't reach USD 5,- included shipping.
K-Ray -- The Journals