Mixing oil weights

Scuder knows a lot more about oil than I do, but I broke in a solid lifter flat tappet engine with a witches brew of on-hand old racing oil, diesel, and a zinc additive and it worked out fine.
I use what I find in the garage. Synthetic for the car that requires it, diesel in the diesels, heavy race oil mixed with lighter car oil or diesel in the race car, primarily to use up the old 50wt race oil, loaded with zinc, that I was gifted.
No problems with anything so far.
Personally, MY opinion only..... I'd use what I have, mix it (especially since it's the same brand,) and run it.