Why not ask Sota?
I have sent an e-mail,I thought somebody here might know.This appears to be the same tonearm that was on the Revolver Rebel and the Ariston Q Deck.It was made by Jelco of Japan and they claim they no longer have any records of these oem arms they produced,over 20 years ago,they stated.The Sota Moonbeam is still in production and it looks like exactly the same arm.Sota infers it is their own original design,but obviously...Jelco now offers the SA-250 arm on their site but only the curved arm tube and the detachable head-shell seem to vary from the old design.Stefanl
The only thing I could find with a web search was a dealer spec for the current Moonbeam/VLMT. They recommended a cartridge weight of 4-10.5 grams, which implies that the VLMT has low-medium effective mass. That would be typical for a mid-market arm designed in the 1970's-80's, when lighter weight, more compliant cartridges were the norm.
I hope my guesswork is useful. If you're cartridge shopping, try to borrow one from someone, mount it up and run the resonance tracks on the HFN test record. That will give you a pretty good idea of whether you need to go lighter/softer or heavier/stiffer. The responses to this thread might be helpful in that vein:
Yes it is interesting that when that arm was on the Ariston Q Deck it was shipped with an Ortofon OM10 which is really the wrong cartridge for it.I worked out that a Denon 103 is the perfect match for the arm with it's low compliance.Since both the tonearm and cartridge come from Japan I wonder if the Denon was the test cartridge,just a thought.