As a first try, why did you start with such a complicated and strange looking riser design? I don’t mean to offend you, but like Shredd said keep it simple and you can always get fancy later.
NO offense taken,
went to a telescope gathering once, a long time ago
then went home and ground/polished,fugured a 28inch Diam, chunk of Black-glass into a mirror, and built a mount for it,
could have just bought one, but getting the final wave-length,thickness figure was a challenge I enjoyed
,
didn't buy a boat, but built my own with my kids,
,
never liked taking the easy road, sure no bumps but,
the hard road was always more interesting, and more lessons learned,
,
Yup, IT may look weird but ill learn, the hard way and hey it is different than most I've seen
and all the wood i had on hand from knife and gunstocks ive made
cheers
John