Here's a list that includes the higher four digit model codes -
http://outdoorpowerinfo.com/engine_specs/tecumseh_carb_mfg_no.aspBut it only brackets your model! However, it's pretty likely that the part number listed for both #1650 and #1652 will fit.
That's P/No 632795A - so just search for 'Tecumseh 632795a' on FleaBay. Plenty of cheap clone carbies out of Hong Kong and China there.