Audi Cabriolet 2.0 ABK - Timing belts

Hello to the round,

after 8 years of V8 and 6 years of abstinence, we got an increase again from Ingolstadt with an Audi Cabriolet 2.0 ABK in our family fleet.

So it comes that after a felt eternity I am once again on the way here in the forum, some old acquaintances are still active, I am happy.

Unfortunately, I can only understand the workshop history conditionally, above all there is no entry in the service booklet about a timing belt change. The Audi is now 24 years old and has 145,000 km down. On the timing belt stands "BOSCH" and then a six-digit number, which unfortunately cannot be read properly. It could be 190704 or 190794.

It is not possible to distinguish between 0 and 9, and between 1 and 4, although the first digit is probably more like 1 and the last is a 4.

Is the fact that BOSCH is on it a hint that it is no longer the first timing belt?

Can someone help me find out when the timing belt is from? The previous owner doesn't know if it was changed, and he drove the Audi for 18 years.

Thank you in advance and greetings,

Mathias