Fred, there’ve been quite a number of posts over the years on the efficacy of Rubidium Clocks when used with the Vivaldi Master Clock. I would recommend that you search the forum and read up on them. Like this for example;
To your specific question though, yes, I’ve done this years ago, at the time with my Scarlatti stack. At the end of the day, a DIY reference Clock with old-parts can’t really compete with current commercial platforms of the day. Best case you won’t hear any improvement, worse case it’ll make things sound worse.