weights on Sumiko MDC800 versus MMT,FT3

Anybody knows if counterweights on those - MMT and FT3/FT4 are interchangeable with MDC800? I have the MDC800 but I only have 1 heavy (H) counterweight, wonder if those from other Sumiko's would fit?
Thank you
Avs9, The MDC 800 was sold with a particular counter weight
depending from the customers cart weight. But there are 5 counter
weights for this tonearm marked with letters: l,m,h,x and a. With L for 6 g.(+/-2), M for 8g.(+-2g.) ,H for 10 g.(+/-2g.), K for 15 g. (+/-2 g.)and A for 18 g. (+/-2 g.).
All those weights share one common decoupler which need to be installed 'in' the weights with the help of a tool called 'wrench'. So you can use your H weight for the carts from 10- 12 g. weight. That is to say with the optimal position of the weight in (co)realtion to the pivot. I am, alas, not familiar with the MMT/ FRT3/FT4 versions but
if their rear armtube is of the same thicknes as by MDC 800 you can of course try.

Addition, Sorry Avs9. I made a typo. You can use your H weight for the carts from 8 g.- 12 g. weight.

Thank you, Nandric, the arm on MDC800 is 10.5 mm as my micrometer shows, the answer about that I got from someone selling FT3 on ebay was 'about 12-13 mm'. On the good side it is not less, but it doesn't look like they are interchangable as is.
Avs9, For your (global) orientation. Each next weight is about 10g. heavier than the previous one. I deduced the difference from 3 known weights. My Sumiko 800 had two weights + the wrench while 'my' machinist made the other
three for me. They are easy (for a machinist) to produce so
everyone who owns this 'better Breuer' should try (to find
some machinist).NB the user manual is available by the vinylengine.