Realised pronouns are a bit of a pain, so I'll leave them in the workshop for a bit. Here are the numerals, almost as painful due to their poor attestation.
Numbers
1. The number one is unstressed but the likely form is
úíns, and might have followed the pronominal declension as Latin
ūnus did. The ordinal number would be either
prismús (would the suncope of ú be blocked by the cluster or what? Maybe become
prisem, prismú, prismúm) or
prúms depending on whether it follows Paelignian or Umbrian, more likely the former as it's more closely related to Oscan.
2. The number two is also unattested. The form may be
duus, duvas, following the plural of o-/ā-stems rather than continuing the dual as in Latin. The word
altter 'other' could likely be used as an ordinal, but it may have had the form
dutis, dutiú, dutim as well. Where Latin has
bi-, Osan most likely had
di-.
3. Oscan
trís (although it should be
tríís) is attested as the masculine and feminine accusative. It has the root
treí- and follows the plural i-stem conjugation. The ordinal would be
tertis, tertiú, tertim.
4. We run into difficulty with four as Wallace and Buck disagree. There are the forms
pettiur (Wallace),
petora (Buck) and
petirú- (both). Wallace's forms could be in the same relation to each other as the n-stem nouns, with -i- in place of -iu- in oblique forms. Buck's form is however easier to explain from the PIt form *kwetwor. Wallace would require a form *kwetur, with samparasana of the *w after syncope, u > ju after a dental and then lengthening of a voiceless stop before /j/. All in all possible but not as likely. Buck also gives a possible cardinal
trutum which believe it or not is explainable as a zero form of the PIE numeral, *kturīya- > *ktru-to- (in which case it would be
turz, turtú, turtúm.
5. From here on the cardinals are indeclinable (not sure about ordinals). Five is
púmpe and its ordinal is
púnz, púntú, púntúm.
6. The cardinal might be
seks (or should it be
sííks?) and the ordinal
sest- (is /sts/ a valid final cluster? I need a way to resolve awkward consonant clusters)
7. There is no evidence for the number seven, but it might be of the form
seftúm, with the ordinal
sefz, seftú, seftúm.
8. The cardinal is probably
úhtu and the ordinal
úhtavis as in the name, although I don't know how likely that is.
9. The ordinal is probably
núvems, núv(e)mú núv(e)múm or something similar, following the cardinal rather than the Latin
nōnus?
10. The cardinal is probably
dekem, with the ordinal
dekems, dekmú, dekmúm although there is also a possible form
deket-.
Edit: Here's a little chart
úíns, úínú, úínúm ... priísmús, priísmú, priísmúm
duus, duvas, duvú ... dutis, duttiú, dutim
tríís, triiú ... tertis, tertiú, tertim
pettiur, petirú ... trutis, truttiú, trutim
púmpe ... púnz, púntú, púntúm
sess ... sestús, sestú, sestúm
seftúm ... seftús, seftú, seftúm
úhtu ... úhtavis, úhtaviú, úhtavim
núvem ... núvems, núvmú núvmúm
dekem ... dekems, dekmú, dekmúm
Unresolved questions: would *prīsmos, *sekstos, *septos keep the o because of the cluster or deal with it in some other way? Also, what about the word
dekez, deketú, deketúm?
Would
duttiú and
truttiú lose or generalise the double tt or just leave it as is? The doubling of consonants before /j/ (and sometimes before /r/ and /w/) seems to be a later development and possibly still productive by 100BCE.