I have an ES truss dob and just purchased a telrad to install. Unfortunately the base is about 1 cm too long and doesn't fit between metal rings on the upper assembly. I have found the dove tail adapters on scope stuff, but they are pricey and I already have a RACI finder attached so I would rather find another option. Are there any alternative bases out there or even a riser that have a slightly smaller (less long) footprint? I love the quality of the telrad, but I suppose if I can't make it work then I will return it in exchange for a Rigel quick finder.