I convert any 120 roll film you choose from my store to 620 format by machining it accurately in a lathe.
The cost of this machining is $15 per roll.
The procedure is:
1/ Choose your films and put them in your cart.
2/ Then, for whatever number of films you chose, add to the cart the same number of 'machinings', from here which is just the labour cost per film.
(Note that some films are sold in 'pairs', count these as 2 when adding to cart)
Checkout and you're done.