Would a Creda fan motor (with the round mounting plate) do the job? I’ve been able to use this motor in loads of different ovens over the years as it has several fitting options. It’s genuine part number is:- 54879 or Electrue part no. 5031680203172 (gen) or MTR8001 pattern. Prices are:- £8.65 +VAT (gen) or £7.75+ VAT (pattern).
Worth a try!!! 😉