We're installing a set of the 1 1/4" guages into an RV4 panel right now. As you know they're made by UMA, and from all indications they appear to be of pretty good quality and better than a lot of the 2 1/4" instruments I've seen.
They are a bit higher in price, but really look nice installed....like litttle turbine indicators!
Anyway we haven't fired them up yet but the fit/finish appears to be quite good. I think the 1 1/4" fuel gauges are becoming a popular option for "backup" fuel gauges on some of the panels we're doing.
Cheers,
Stein.