Combine two tickers OHLC bars with selectable sources

Combines the bars of two chosen tickers, used to fix issues with split history, new ticker names

e.g. MYTIL went to LSE from ATHEX and changed ticker names but with "broken"/ split chart history. With this script you get the full history combined with the two tickers.

An SMA50 was used as an example of how this can be used with others custom indicators inside this script.