We could not even start to guess as age has nothing to do with performance. Your question should have been answered by a fitter for optimum golf head and shaft selection. Anything else will just be an expensive trial and error. Hopefully if you went by what you think will be a good fit, you will have success and at least a better set up than your previous one. Just changing to the lighter head and more flexible shaft may give you greater distance than the older club but you might also lose some accuracy. We have no way to know for sure as everyone's swing is different. Hope it works out for you and you have many more enjoyable rounds.

Well, age does affect performance, but, yes, not all 70 year olds are the same.

As noted by Dale, there is no predictability for how the change will alter your drives. The stock TSR-1 is a 40 g matrix MCA shaft. If the driver you bought a TSR-1 with a 70 g shaft that was not fitted for you hon you might not get much benefit. Since few 70 year olds have a swing speed of over 95 mph, almost all that are fitted and when determined that the -1 is a better option than the TSR-2, most will be fitted to shafts in the 40-50 g range. A 70 g shaft detracts from the lightweight setup to help goose club head speed.

Empirically I should use a TSR-1 with a light shaft. But I kept losing the feel of the head and we couldn’t get spin under 3000 rpm’s. Ended up with a TSR-2, but that’s just me.