EUR values before the EUR

[oldirtybasti]

I have a brokerage account with base currency EUR. My data provider (Norgate) has EURUSD rate back till 1991. As I intend to run backtests with data back to the eighties, I wonder what to do here. The wikipedia article https://en.wikipedia.org/wiki/European_Currency_Unit states that the EUR was pegged to 8 currencies from 1979 to 1989 and 12 currencies from 1989 to 1998. I assume that Norgate calculates the EUR rate before it came into existence in 1999 by using the pegs.

My question is whether anybody knows where I can find a EUR rate going back to 1979. Does this even make sense or should I not bother and do the backtest in USD. Difference should be small I guess.