Mark,
I don't recall singling you out, but... Facts are, I have spent a ton of money with Streetly and a substantial amount with Marcus (I don't really consider Dave as an active part of the production/sales side of MA). Because I repair/restore M-400s on occasion, I have reason to do so. I also have a fairly decent inventory of spare parts as well as eight tape frames and three other tape sets.
However, I have spoke or corresponded with Mellotron owners on and off the list who are just plain reluctant to invest in anything beyond owning a Mellotron for the sake of owning one. Unfortunately for us in the US, the American dollar is performing poorly against other currencies, especially the British Pound Sterling. This has got to make it doubly tough on Streetly's ability to market to the US.
You may want to consider that a lot of Tron owners come to this list after acquiring their machines.
Lastly, in support of Streetly, I will tell you that They are building their business without the resources that Dave Kean had. They were/are strictly a self contained enterprise that has continuously reinvested its income into developing new sounds and new parts. Soon there will be new machines as well. I am sure, as with everything else I have ever seen from them, the quality will be second to none.
An, although Markus is a great guy and a terrific craftsman and innovator, there have been no new additions to the world library of Mellotron sounds from MA. Also, the first Mark IV didn't just show up out of the blue. It took a long time to produce the prototype. Then, once production began, it is well known that the first machines were inundated with problems that seemingly took a couple of years to finally get the bugs worked out. Perhaps Streetly is being a bit more cautious with so much at stake. Finally, Streetly has built its business on the acquisition, restoration and resale of existing machines. There is certainly no one more capable then they to do so.
If you purchase new rollers or other parts from MA, solved your problems and are happy, so be it. As for Andy, he is a frequent and positive contributor to this list. He is also a musician who uses his Mellotron for its intended purpose. He also obviously has other financial responsibilities that limit how much he has to invest in his machine,as do most of us.
Enjoy your Mellotron. I think you have beat whatever point you are trying to make into the ground.
Peace,
Frank