The Venturi VP is not ideal but it works. You can do it in stages, I did. The bottom line is that you don't need perfect vacuum for A/C to work. Some shade tree mechanic charges the system without pulling any vacuum, just release the air from the high side port. It still works. Just buy something reasonable you can afford and is up to spec because most DIY only uses it very rarely. It is not you are fixing your A/C every month.

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Not MBZ nor A/C trained professional but a die-hard DIY and green engineer. Use the info at your own peril. Picked up 2 Infractions because of disagreements. NOW reversed.

W124 Keyless remote, PM for details. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/334620-fs-w124-chasis-keyless-remote-%2450-shipped.html

1 X 2006 CDI
1 x 87 300SDL
1 x 87 300D
1 x 87 300TDT wagon
1 x 83 300D
1 x 84 190D ( 5 sp ) - All R134 converted + keyless entry.