diff --git a/geant3/src/lemsr/gukine.F b/geant3/src/lemsr/gukine.F
index 941df12..fa92a57 100644
--- a/geant3/src/lemsr/gukine.F
+++ b/geant3/src/lemsr/gukine.F
@@ -38,6 +38,7 @@ c                               ! rotated e+-momenta
       real*4       ubuf(nubuf)
       real*4       random_1(3), random_2(7)
       real*4       sigma_p
+      real*4       off
 c
 ccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc
 c
@@ -70,7 +71,8 @@ c
 c           Cu ring of sample (z/2 = 0.2cm) at z = 1.6 cm
 c           MCP Hamamatsu Z-stack (z/2 = 0.12cm) at z = 1.52 cm
 c
-            z0 = +1.40002 ! the Hamamatsu, Galileo MCP's end and sample end is at z=1.40cm now
+            off = 0.
+            z0  = +1.40002+off ! the Hamamatsu, Galileo MCP's end and sample end is at z=1.40cm now
 c                       ! z=1.40002 corresponds to an implatation depth of the
 c                       ! mu+ of 200 nm.
 c
diff --git a/geant3/src/lemsr/ugeom.F b/geant3/src/lemsr/ugeom.F
index fee2751..ff509de 100644
--- a/geant3/src/lemsr/ugeom.F
+++ b/geant3/src/lemsr/ugeom.F
@@ -684,16 +684,14 @@ c
 c       position of sample cryo things
 c
 c       off = 0.25
-        off = 0.0
+        off = 0.
         if ( l_samp ) then
-            call gspos('SAH3',1,'MCPV',0.,0.,+1.35,0,'ONLY')
-            call gspos('SAH2',1,'MCPV',0.,0.,+1.6,0,'ONLY')
-            call gspos('SAPH',1,'MCPV',0.,0.,+2.1,0,'ONLY')
+c            call gspos('SAH3',1,'MCPV',0.,0.,+1.35+off,0,'ONLY')
+            call gspos('SAH2',1,'MCPV',0.,0.,+1.6+off,0,'ONLY')
+            call gspos('SAPH',1,'MCPV',0.,0.,+2.1+off,0,'ONLY')
             call gspos('SAH1',1,'MCPV',0.,0.,+2.65+off,0,'ONLY')
         endif
 c
-c       off = 0.5
-        off = 0.0
         if ( l_cryo ) then      ! parts of the CryoVac cryostat
             call gspos('COFI',1,'MCPV',0.,0.,+3.40+off,0,'ONLY')
             call gspos('CRY1',1,'MCPV',0.,0.,+4.25+off,0,'ONLY')
@@ -703,7 +701,7 @@ c       off = 0.5
         endif
 c
         if ( l_crsh ) then 
-            call gspos('CRSH',1,'MCPV',0.,0.,+1.6,0,'ONLY')
+            call gspos('CRSH',1,'MCPV',0.,0.,+1.6+off,0,'ONLY')
         endif
 c
 c       position of MCP